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class="toctree-l3"><a class="reference internal" href="../tutorial/perform-findAndModify-linearizable-reads.html">Linearizable Reads via <code class="docutils literal"><span class="pre">findAndModify</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../core/query-plans.html">Query Plans</a></li><li class="toctree-l3"><a class="reference internal" href="../core/query-optimization.html">Query Optimization</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/evaluate-operation-performance.html">Evaluate Performance of Current Operations</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/optimize-query-performance-with-indexes-and-projections.html">Optimize Query Performance</a></li><li class="toctree-l4"><a class="reference internal" href="../core/write-performance.html">Write Operation Performance</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/explain-results.html">Explain Results</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/analyze-query-plan.html">Analyze Query Performance</a></li><li class="toctree-l3"><a class="reference internal" href="../core/tailable-cursors.html">Tailable Cursors</a></li></ul></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../aggregation.html">Aggregation</a><ul><li class="toctree-l2"><a class="reference internal" href="../core/aggregation-pipeline.html">Aggregation Pipeline</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/aggregation-pipeline-optimization.html">Aggregation Pipeline Optimization</a></li><li class="toctree-l3"><a class="reference internal" href="../core/aggregation-pipeline-limits.html">Aggregation Pipeline Limits</a></li><li class="toctree-l3"><a class="reference internal" href="../core/aggregation-pipeline-sharded-collections.html">Aggregation Pipeline and Sharded Collections</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/aggregation-zip-code-data-set.html">Example with ZIP Code Data</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/aggregation-with-user-preference-data.html">Example with User Preference Data</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/map-reduce.html">Map-Reduce</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/map-reduce-sharded-collections.html">Map-Reduce and Sharded Collections</a></li><li class="toctree-l3"><a class="reference internal" href="../core/map-reduce-concurrency.html">Map-Reduce Concurrency</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/map-reduce-examples.html">Map-Reduce Examples</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/perform-incremental-map-reduce.html">Perform Incremental Map-Reduce</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/troubleshoot-map-function.html">Troubleshoot the Map Function</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/troubleshoot-reduce-function.html">Troubleshoot the Reduce Function</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/aggregation.html">Aggregation Reference</a><ul><li class="toctree-l3"><a class="reference internal" href="../meta/aggregation-quick-reference.html">Aggregation Pipeline Quick Reference</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/operator/aggregation/interface.html">Aggregation Commands</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/aggregation-commands-comparison.html">Aggregation Commands Comparison</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/aggregation-variables.html">Variables in Aggregation Expressions</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/sql-aggregation-comparison.html">SQL to Aggregation Mapping Chart</a></li></ul></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../data-modeling.html">Data Models</a><ul><li class="toctree-l2"><a class="reference internal" href="../core/data-modeling-introduction.html">Data Modeling Introduction</a></li><li class="toctree-l2"><a class="reference internal" href="../core/schema-validation.html">Schema Validation</a></li><li class="toctree-l2"><a class="reference internal" href="../core/data-models.html">Data Modeling Concepts</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/data-model-design.html">Data Model Design</a></li><li class="toctree-l3"><a class="reference internal" href="../core/data-model-operations.html">Operational Factors and Data Models</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../applications/data-models.html">Data Model Examples and Patterns</a><ul><li class="toctree-l3"><a class="reference internal" href="../applications/data-models-relationships.html">Model Relationships Between Documents</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-embedded-one-to-one-relationships-between-documents.html">Model One-to-One Relationships with Embedded Documents</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-embedded-one-to-many-relationships-between-documents.html">Model One-to-Many Relationships with Embedded Documents</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-referenced-one-to-many-relationships-between-documents.html">Model One-to-Many Relationships with Document References</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../applications/data-models-tree-structures.html">Model Tree Structures</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-tree-structures-with-parent-references.html">Model Tree Structures with Parent References</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-tree-structures-with-child-references.html">Model Tree Structures with Child References</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-tree-structures-with-ancestors-array.html">Model Tree Structures with an Array of Ancestors</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-tree-structures-with-materialized-paths.html">Model Tree Structures with Materialized Paths</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-tree-structures-with-nested-sets.html">Model Tree Structures with Nested Sets</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../applications/data-models-applications.html">Model Specific Application Contexts</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-data-for-atomic-operations.html">Model Data for Atomic Operations</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-data-for-keyword-search.html">Model Data to Support Keyword Search</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-data-for-schema-versioning.html">Model Data for Schema Versioning</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-monetary-data.html">Model Monetary Data</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-time-data.html">Model Time Data</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/model-computed-data.html">Model Computed Data</a></li></ul></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/data-models.html">Data Model Reference</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/database-references.html">Database References</a></li></ul></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../core/transactions.html">Transactions</a><ul><li class="toctree-l2"><a class="reference internal" href="../core/transactions-in-applications.html">Drivers API</a></li><li class="toctree-l2"><a class="reference internal" href="../core/transactions-production-consideration.html">Production Considerations</a></li><li class="toctree-l2"><a class="reference internal" href="../core/transactions-sharded-clusters.html">Production Considerations (Sharded Clusters)</a></li><li class="toctree-l2"><a class="reference internal" href="../core/transactions-operations.html">Transactions and Operations</a></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../indexes.html">Indexes</a><ul><li class="toctree-l2"><a class="reference internal" href="../core/index-single.html">Single Field Indexes</a></li><li class="toctree-l2"><a class="reference internal" href="../core/index-compound.html">Compound Indexes</a></li><li class="toctree-l2"><a class="reference internal" href="../core/index-multikey.html">Multikey Indexes</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/multikey-index-bounds.html">Multikey Index Bounds</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/index-text.html">Text Indexes</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/specify-language-for-text-index.html">Specify a Language for Text Index</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/avoid-text-index-name-limit.html">Specify Name for <code class="docutils literal"><span class="pre">text</span></code> Index</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/control-results-of-text-search.html">Control Search Results with Weights</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/limit-number-of-items-scanned-for-text-search.html">Limit the Number of Entries Scanned</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/index-wildcard.html">Wildcard Indexes</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/index-wildcard-restrictions.html">Wildcard Index Restrictions</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/2dsphere.html"><code class="docutils literal"><span class="pre">2dsphere</span></code> Indexes</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/query-a-2dsphere-index.html">Query a <code class="docutils literal"><span class="pre">2dsphere</span></code> Index</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/2d.html"><code class="docutils literal"><span class="pre">2d</span></code> Indexes</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/build-a-2d-index.html">Create a <code class="docutils literal"><span class="pre">2d</span></code> Index</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/query-a-2d-index.html">Query a <code class="docutils literal"><span class="pre">2d</span></code> Index</a></li><li class="toctree-l3"><a class="reference internal" href="../core/geospatial-indexes.html"><code class="docutils literal"><span class="pre">2d</span></code> Index Internals</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/calculate-distances-using-spherical-geometry-with-2d-geospatial-indexes.html">Calculate Distance Using Spherical Geometry</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/geohaystack.html"><code class="docutils literal"><span class="pre">geoHaystack</span></code> Indexes</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/build-a-geohaystack-index.html">Create a Haystack Index</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/query-a-geohaystack-index.html">Query a Haystack Index</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/index-hashed.html">Hashed Indexes</a></li><li class="toctree-l2"><a class="reference internal" href="../core/index-properties.html">Index Properties</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/index-ttl.html">TTL Indexes</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/expire-data.html">Expire Data from Collections by Setting TTL</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../core/index-unique.html">Unique Indexes</a></li><li class="toctree-l3"><a class="reference internal" href="../core/index-partial.html">Partial Indexes</a></li><li class="toctree-l3"><a class="reference internal" href="../core/index-case-insensitive.html">Case Insensitive Indexes</a></li><li class="toctree-l3"><a class="reference internal" href="../core/index-sparse.html">Sparse Indexes</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/index-creation.html">Index Builds on Populated Collections</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/build-indexes-on-replica-sets.html">Build Indexes on Replica Sets</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/build-indexes-on-sharded-clusters.html">Build Indexes on Sharded Clusters</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/index-intersection.html">Index Intersection</a></li><li class="toctree-l2"><a class="reference internal" href="../tutorial/manage-indexes.html">Manage Indexes</a></li><li class="toctree-l2"><a class="reference internal" href="../tutorial/measure-index-use.html">Measure Index Use</a></li><li class="toctree-l2"><a class="reference internal" href="../applications/indexes.html">Indexing Strategies</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/create-indexes-to-support-queries.html">Create Indexes to Support Your Queries</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/sort-results-with-indexes.html">Use Indexes to Sort Query Results</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/ensure-indexes-fit-ram.html">Ensure Indexes Fit in RAM</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/create-queries-that-ensure-selectivity.html">Create Queries that Ensure Selectivity</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/indexes.html">Indexing Reference</a></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../security.html">Security</a><ul><li class="toctree-l2"><a class="reference internal" href="../administration/security-checklist.html">Security Checklist</a></li><li class="toctree-l2"><a class="reference internal" href="../tutorial/enable-authentication.html">Enable Access Control</a></li><li class="toctree-l2"><a class="reference internal" href="../core/authentication.html">Authentication</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/security-users.html">Users</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/create-users.html">Add Users</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../core/authentication-mechanisms.html">Authentication Mechanisms</a><ul><li class="toctree-l4"><a class="reference internal" href="../core/security-scram.html">SCRAM</a></li><li class="toctree-l4"><a class="reference internal" href="../core/security-x.509.html">x.509</a><ul><li class="toctree-l5"><a class="reference internal" href="../tutorial/configure-x509-client-authentication.html">Use x.509 Certificates to Authenticate Clients</a></li></ul></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../core/authentication-mechanisms-enterprise.html">Enterprise Authentication Mechanisms</a><ul><li class="toctree-l4"><a class="reference internal" href="../core/kerberos.html">Kerberos Authentication</a><ul><li class="toctree-l5"><a class="reference internal" href="../tutorial/control-access-to-mongodb-with-kerberos-authentication.html">Configure MongoDB with Kerberos Authentication on Linux</a></li><li class="toctree-l5"><a class="reference internal" href="../tutorial/control-access-to-mongodb-windows-with-kerberos-authentication.html">Configure MongoDB with Kerberos Authentication on Windows</a></li><li class="toctree-l5"><a class="reference internal" href="../tutorial/troubleshoot-kerberos.html">Troubleshoot Kerberos Authentication</a></li><li class="toctree-l5"><a class="reference internal" href="../tutorial/kerberos-auth-activedirectory-authz.html">Configure MongoDB with Kerberos Authentication and Active Directory Authorization</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../core/security-ldap.html">LDAP Proxy Authentication</a><ul><li class="toctree-l5"><a class="reference internal" href="../tutorial/configure-ldap-sasl-activedirectory.html">Authenticate Using SASL and LDAP with ActiveDirectory</a></li><li class="toctree-l5"><a class="reference internal" href="../tutorial/configure-ldap-sasl-openldap.html">Authenticate Using SASL and LDAP with OpenLDAP</a></li><li class="toctree-l5"><a class="reference internal" href="../tutorial/authenticate-nativeldap-activedirectory.html">Authenticate and Authorize Users Using Active Directory via Native LDAP</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../core/security-ldap-external.html">LDAP Authorization</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../core/security-internal-authentication.html">Internal/Membership Authentication</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/deploy-replica-set-with-keyfile-access-control.html">Deploy Replica Set With Keyfile Authentication</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/enforce-keyfile-access-control-in-existing-replica-set.html">Update Replica Set to Keyfile Authentication</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/enforce-keyfile-access-control-in-existing-replica-set-without-downtime.html">Update Replica Set to Keyfile Authentication (No Downtime)</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/rotate-key-replica-set.html">Rotate Keys for Replica Sets</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/deploy-sharded-cluster-with-keyfile-access-control.html">Deploy Sharded Cluster with Keyfile Authentication</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/enforce-keyfile-access-control-in-existing-sharded-cluster.html">Update Sharded Cluster to Keyfile Authentication</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/enforce-keyfile-access-control-in-existing-sharded-cluster-no-downtime.html">Update Sharded Cluster to Keyfile Authentication (No Downtime)</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/rotate-key-sharded-cluster.html">Rotate Keys for Sharded Clusters</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/configure-x509-member-authentication.html">Use x.509 Certificate for Membership Authentication</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/upgrade-keyfile-to-x509.html">Upgrade from Keyfile Authentication to x.509 Authentication</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/rotate-x509-membership-certificates.html">Rolling Update of x.509 Cluster Certificates that Contain New DN</a></li></ul></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/authorization.html">Role-Based Access Control</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/built-in-roles.html">Built-In Roles</a></li><li class="toctree-l3"><a class="reference internal" href="../core/security-user-defined-roles.html">User-Defined Roles</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/manage-users-and-roles.html">Manage Users and Roles</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/change-own-password-and-custom-data.html">Change Your Password and Custom Data</a></li><li class="toctree-l3"><a class="reference internal" href="../core/collection-level-access-control.html">Collection-Level Access Control</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/security-transport-encryption.html">TLS/SSL (Transport Encryption)</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-ssl.html">Configure <code class="docutils literal"><span class="pre">mongod</span></code> and <code class="docutils literal"><span class="pre">mongos</span></code> for TLS/SSL</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-ssl-clients.html">TLS/SSL Configuration for Clients</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/upgrade-cluster-to-ssl.html">Upgrade a Cluster to Use TLS/SSL</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-fips.html">Configure MongoDB for FIPS</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/security-encryption-at-rest.html">Encryption at Rest</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-encryption.html">Configure Encryption</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/rotate-encryption-key.html">Rotate Encryption Keys</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/security-client-side-encryption.html">Client-Side Field Level Encryption</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/security-automatic-client-side-encryption.html">Automatic Client-Side Field Level Encryption</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/security-client-side-automatic-json-schema.html">Automatic Encryption Rules</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/security-client-side-query-aggregation-support.html">Read/Write Support with Automatic Field Level Encryption</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/security-client-side-encryption-appendix.html">Appendix</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../core/security-explicit-client-side-encryption.html">Explicit (Manual) Client-Side Field Level Encryption</a></li><li class="toctree-l3"><a class="reference internal" href="../core/security-client-side-encryption-key-management.html">Master Key and Data Encryption Key Management</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/manage-client-side-encryption-data-keys.html">Manage Data Encryption Keys</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/security-client-side-encryption-limitations.html">Limitations</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/auditing.html">Auditing</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-auditing.html">Configure Auditing</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-audit-filters.html">Configure Audit Filters</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/audit-message.html">System Event Audit Messages</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/security-hardening.html">Network and Configuration Hardening</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/security-mongodb-configuration.html">IP Binding</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-linux-iptables-firewall.html">Configure Linux <code class="docutils literal"><span class="pre">iptables</span></code> Firewall for MongoDB</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-windows-netsh-firewall.html">Configure Windows <code class="docutils literal"><span class="pre">netsh</span></code> Firewall for MongoDB</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../tutorial/implement-field-level-redaction.html">Implement Field Level Redaction</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/security.html">Security Reference</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/system-roles-collection.html"><code class="docutils literal"><span class="pre">system.roles</span></code> Collection</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/system-users-collection.html"><code class="docutils literal"><span class="pre">system.users</span></code> Collection</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/resource-document.html">Resource Document</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/privilege-actions.html">Privilege Actions</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../tutorial/create-a-vulnerability-report.html">Create a Vulnerability Report</a></li><li class="toctree-l2"><a class="reference internal" href="../appendix/security.html">Appendix</a><ul><li class="toctree-l3"><a class="reference internal" href="../appendix/security/appendixA-openssl-ca.html">Appendix A - OpenSSL CA Certificate for Testing</a></li><li class="toctree-l3"><a class="reference internal" href="../appendix/security/appendixB-openssl-server.html">Appendix B - OpenSSL Server Certificates for Testing</a></li><li class="toctree-l3"><a class="reference internal" href="../appendix/security/appendixC-openssl-client.html">Appendix C - OpenSSL Client Certificates for Testing</a></li></ul></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../changeStreams.html">Change Streams</a><ul><li class="toctree-l2"><a class="reference internal" href="../administration/change-streams-production-recommendations.html">Change Streams Production Recommendations</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/change-events.html">Change Events</a></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../replication.html">Replication</a><ul><li class="toctree-l2"><a class="reference internal" href="../core/replica-set-members.html">Replica Set Members</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/replica-set-primary.html">Replica Set Primary</a></li><li class="toctree-l3"><a class="reference internal" href="../core/replica-set-secondary.html">Replica Set Secondary Members</a><ul><li class="toctree-l4"><a class="reference internal" href="../core/replica-set-priority-0-member.html">Priority 0 Replica Set Members</a></li><li class="toctree-l4"><a class="reference internal" href="../core/replica-set-hidden-member.html">Hidden Replica Set Members</a></li><li class="toctree-l4"><a class="reference internal" href="../core/replica-set-delayed-member.html">Delayed Replica Set Members</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../core/replica-set-arbiter.html">Replica Set Arbiter</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/replica-set-oplog.html">Replica Set Oplog</a></li><li class="toctree-l2"><a class="reference internal" href="../core/replica-set-sync.html">Replica Set Data Synchronization</a></li><li class="toctree-l2"><a class="reference internal" href="../core/replica-set-architectures.html">Replica Set Deployment Architectures</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/replica-set-architecture-three-members.html">Three Member Replica Sets</a></li><li class="toctree-l3"><a class="reference internal" href="../core/replica-set-architecture-geographically-distributed.html">Replica Sets Distributed Across Two or More Data Centers</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/replica-set-high-availability.html">Replica Set High Availability</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/replica-set-elections.html">Replica Set Elections</a></li><li class="toctree-l3"><a class="reference internal" href="../core/replica-set-rollbacks.html">Rollbacks During Replica Set Failover</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../applications/replication.html">Replica Set Read and Write Semantics</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/replica-set-write-concern.html">Write Concern for Replica Sets</a></li><li class="toctree-l3"><a class="reference internal" href="../core/read-preference.html">Read Preference</a><ul><li class="toctree-l4"><a class="reference internal" href="../core/read-preference-tags.html">Tag Sets</a></li><li class="toctree-l4"><a class="reference internal" href="../core/read-preference-staleness.html">maxStalenessSeconds</a></li><li class="toctree-l4"><a class="reference internal" href="../core/read-preference-use-cases.html">Read Preference Use Cases</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../core/read-preference-mechanics.html">Server Selection Algorithm</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../administration/replica-set-deployment.html">Replica Set Deployment Tutorials</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/deploy-replica-set.html">Deploy a Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/deploy-replica-set-for-testing.html">Deploy a Replica Set for Testing and Development</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/deploy-geographically-distributed-replica-set.html">Deploy a Geographically Redundant Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/add-replica-set-arbiter.html">Add an Arbiter to Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/convert-standalone-to-replica-set.html">Convert a Standalone to a Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/expand-replica-set.html">Add Members to a Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/remove-replica-set-member.html">Remove Members from Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/replace-replica-set-member.html">Replace a Replica Set Member</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../administration/replica-set-member-configuration.html">Member Configuration Tutorials</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/adjust-replica-set-member-priority.html">Adjust Priority for Replica Set Member</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-secondary-only-replica-set-member.html">Prevent Secondary from Becoming Primary</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-a-hidden-replica-set-member.html">Configure a Hidden Replica Set Member</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-a-delayed-replica-set-member.html">Configure a Delayed Replica Set Member</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-a-non-voting-replica-set-member.html">Configure Non-Voting Replica Set Member</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/convert-secondary-into-arbiter.html">Convert a Secondary to an Arbiter</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../administration/replica-set-maintenance.html">Replica Set Maintenance Tutorials</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/change-oplog-size.html">Change the Size of the Oplog</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/perform-maintence-on-replica-set-members.html">Perform Maintenance on Replica Set Members</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/force-member-to-be-primary.html">Force a Member to Become Primary</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/resync-replica-set-member.html">Resync a Member of a Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-replica-set-tag-sets.html">Configure Replica Set Tag Sets</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/reconfigure-replica-set-with-unavailable-members.html">Reconfigure a Replica Set with Unavailable Members</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/manage-chained-replication.html">Manage Chained Replication</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/change-hostnames-in-a-replica-set.html">Change Hostnames in a Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/configure-replica-set-secondary-sync-target.html">Configure a Secondary’s Sync Target</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/replication.html">Replication Reference</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/replica-configuration.html">Replica Set Configuration</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/replica-set-protocol-versions.html">Replica Set Protocol Version</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/troubleshoot-replica-sets.html">Troubleshoot Replica Sets</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/local-database.html">The <code class="docutils literal"><span class="pre">local</span></code> Database</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/replica-states.html">Replica Set Member States</a></li></ul></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../sharding.html">Sharding</a><ul><li class="toctree-l2"><a class="reference internal" href="../core/sharded-cluster-components.html">Sharded Cluster Components</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/sharded-cluster-shards.html">Shards</a></li><li class="toctree-l3"><a class="reference internal" href="../core/sharded-cluster-config-servers.html">Config Servers (metadata)</a></li><li class="toctree-l3"><a class="reference internal" href="../core/sharded-cluster-query-router.html">Router (mongos)</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/sharding-shard-key.html">Shard Keys</a></li><li class="toctree-l2"><a class="reference internal" href="../core/hashed-sharding.html">Hashed Sharding</a></li><li class="toctree-l2"><a class="reference internal" href="../core/ranged-sharding.html">Ranged Sharding</a></li><li class="toctree-l2"><a class="reference internal" href="../tutorial/deploy-shard-cluster.html">Deploy a Sharded Cluster</a></li><li class="toctree-l2"><a class="reference internal" href="../core/zone-sharding.html">Zones</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/manage-shard-zone.html">Manage Shard Zones</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/sharding-segmenting-data-by-location.html">Segmenting Data by Location</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/sharding-tiered-hardware-for-varying-slas.html">Tiered Hardware for Varying SLA or SLO</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/sharding-segmenting-shards.html">Segmenting Data by Application or Customer</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/sharding-high-availability-writes.html">Distributed Local Writes for Insert Only Workloads</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/sharding-data-partitioning.html">Data Partitioning with Chunks</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/create-chunks-in-sharded-cluster.html">Create Chunks in a Sharded Cluster</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/split-chunks-in-sharded-cluster.html">Split Chunks in a Sharded Cluster</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/merge-chunks-in-sharded-cluster.html">Merge Chunks in a Sharded Cluster</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/modify-chunk-size-in-sharded-cluster.html">Modify Chunk Size in a Sharded Cluster</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/sharding-balancer-administration.html">Balancer</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/manage-sharded-cluster-balancer.html">Manage Sharded Cluster Balancer</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/migrate-chunks-in-sharded-cluster.html">Migrate Chunks in a Sharded Cluster</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../administration/sharded-cluster-administration.html">Administration</a><ul><li class="toctree-l3"><a class="reference internal" href="../administration/sharded-cluster-config-servers.html">Config Server Administration</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/replace-config-server.html">Replace a Config Server</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/view-sharded-cluster-configuration.html">View Cluster Configuration</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/restart-sharded-cluster.html">Restart a Sharded Cluster</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/migrate-sharded-cluster-to-new-hardware.html">Migrate a Sharded Cluster to Different Hardware</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/add-shards-to-shard-cluster.html">Add Shards to a Cluster</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/remove-shards-from-cluster.html">Remove Shards from an Existing Sharded Cluster</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/clear-jumbo-flag.html">Clear <code class="docutils literal"><span class="pre">jumbo</span></code> Flag</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/backup-sharded-cluster-metadata.html">Back Up Cluster Metadata</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/convert-sharded-cluster-to-replica-set.html">Convert Sharded Cluster to Replica Set</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/convert-replica-set-to-replicated-shard-cluster.html">Convert a Replica Set to a Sharded Cluster</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/convert-shard-standalone-to-shard-replica-set.html">Convert a Shard Standalone to a Shard Replica Set</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/sharding.html">Sharding Reference</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/sharded-cluster-requirements.html">Operational Restrictions</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/troubleshoot-sharded-clusters.html">Troubleshoot Sharded Clusters</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/config-database.html">Config Database</a></li></ul></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../administration.html">Administration</a><ul><li class="toctree-l2"><a class="reference internal" href="../administration/production-notes.html">Production Notes</a></li><li class="toctree-l2"><a class="reference internal" href="../administration/production-checklist-operations.html">Operations Checklist</a></li><li class="toctree-l2"><a class="reference internal" href="../administration/production-checklist-development.html">Development Checklist</a></li><li class="toctree-l2"><a class="reference internal" href="../administration/analyzing-mongodb-performance.html">Performance</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/manage-the-database-profiler.html">Database Profiler</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/database-profiler.html">Database Profiler Output</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/transparent-huge-pages.html">Disable Transparent Huge Pages (THP)</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/ulimit.html">UNIX <code class="docutils literal"><span class="pre">ulimit</span></code> Settings</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../administration/configuration-and-maintenance.html">Configuration and Maintenance</a><ul><li class="toctree-l3"><a class="reference internal" href="../administration/configuration.html">Run-time Database Configuration</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/upgrade-revision.html">Upgrade to the Latest Revision of MongoDB</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/manage-mongodb-processes.html">Manage <code class="docutils literal"><span class="pre">mongod</span></code> Processes</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/terminate-running-operations.html">Terminate Running Operations</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/rotate-log-files.html">Rotate Log Files</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../data-center-awareness.html">Data Center Awareness</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/workload-isolation.html">Workload Isolation in MongoDB Deployments</a></li><li class="toctree-l3"><a class="reference internal" href="../core/zone-sharding.html">Zones</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/manage-shard-zone.html">Manage Shard Zones</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/sharding-segmenting-data-by-location.html">Segmenting Data by Location</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/sharding-tiered-hardware-for-varying-slas.html">Tiered Hardware for Varying SLA or SLO</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/sharding-segmenting-shards.html">Segmenting Data by Application or Customer</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/sharding-high-availability-writes.html">Distributed Local Writes for Insert Only Workloads</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/manage-shard-zone.html">Manage Shard Zones</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/backups.html">MongoDB Backup Methods</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/backup-with-filesystem-snapshots.html">Back Up and Restore with Filesystem Snapshots</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/backup-and-restore-tools.html">Back Up and Restore with MongoDB Tools</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/restore-replica-set-from-backup.html">Restore a Replica Set from MongoDB Backups</a></li><li class="toctree-l3"><a class="reference internal" href="../administration/backup-sharded-clusters.html">Backup and Restore Sharded Clusters</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/backup-sharded-cluster-with-filesystem-snapshots.html">Back Up a Sharded Cluster with File System Snapshots</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/backup-sharded-cluster-with-database-dumps.html">Back Up a Sharded Cluster with Database Dumps</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/schedule-backup-window-for-sharded-clusters.html">Schedule Backup Window for Sharded Clusters</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/restore-sharded-cluster.html">Restore a Sharded Cluster</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/recover-data-following-unexpected-shutdown.html">Recover a Standalone after an Unexpected Shutdown</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../administration/monitoring.html">Monitoring for MongoDB</a><ul><li class="toctree-l3"><a class="reference internal" href="../administration/free-monitoring.html">Free Monitoring</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/monitor-with-snmp.html">Monitor MongoDB With SNMP on Linux</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/monitor-with-snmp-on-windows.html">Monitor MongoDB Windows with SNMP</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/troubleshoot-snmp.html">Troubleshoot SNMP</a></li></ul></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../storage.html">Storage</a><ul><li class="toctree-l2"><a class="reference internal" href="../core/storage-engines.html">Storage Engines</a><ul><li class="toctree-l3"><a class="reference internal" href="../core/wiredtiger.html">WiredTiger Storage Engine</a><ul><li class="toctree-l4"><a class="reference internal" href="../tutorial/change-standalone-wiredtiger.html">Change Standalone to WiredTiger</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/change-replica-set-wiredtiger.html">Change Replica Set to WiredTiger</a></li><li class="toctree-l4"><a class="reference internal" href="../tutorial/change-sharded-cluster-wiredtiger.html">Change Sharded Cluster to WiredTiger</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../core/inmemory.html">In-Memory Storage Engine</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/journaling.html">Journaling</a><ul><li class="toctree-l3"><a class="reference internal" href="../tutorial/manage-journaling.html">Manage Journaling</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../core/gridfs.html">GridFS</a></li><li class="toctree-l2"><a class="reference internal" href="../faq/storage.html">FAQ: MongoDB Storage</a></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../faq.html">Frequently Asked Questions</a><ul><li class="toctree-l2"><a class="reference internal" href="../faq/fundamentals.html">FAQ: MongoDB Fundamentals</a></li><li class="toctree-l2"><a class="reference internal" href="../faq/indexes.html">FAQ: Indexes</a></li><li class="toctree-l2"><a class="reference internal" href="../faq/concurrency.html">FAQ: Concurrency</a></li><li class="toctree-l2"><a class="reference internal" href="../faq/sharding.html">FAQ: Sharding with MongoDB</a></li><li class="toctree-l2"><a class="reference internal" href="../faq/replica-sets.html">FAQ: Replication and Replica Sets</a></li><li class="toctree-l2"><a class="reference internal" href="../faq/storage.html">FAQ: MongoDB Storage</a></li><li class="toctree-l2"><a class="reference internal" href="../faq/diagnostics.html">FAQ: MongoDB Diagnostics</a></li></ul></li><li class="toctree-l1"><a class="reference internal" href="../reference.html">Reference</a><ul><li class="toctree-l2"><a class="reference internal" href="../reference/operator.html">Operators</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/operator/query.html">Query and Projection Operators</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/operator/query-comparison.html">Comparison Query Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/eq.html">$eq</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/gt.html">$gt</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/gte.html">$gte</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/in.html">$in</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/lt.html">$lt</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/lte.html">$lte</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/ne.html">$ne</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/nin.html">$nin</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/query-logical.html">Logical Query Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/and.html">$and</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/not.html">$not</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/nor.html">$nor</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/or.html">$or</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/query-element.html">Element Query Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/exists.html">$exists</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/type.html">$type</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/query-evaluation.html">Evaluation Query Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/expr.html">$expr</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/jsonSchema.html">$jsonSchema</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/mod.html">$mod</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/regex.html">$regex</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/text.html">$text</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/where.html">$where</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/query-geospatial.html">Geospatial Query Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/geoIntersects.html">$geoIntersects</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/geoWithin.html">$geoWithin</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/near.html">$near</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/nearSphere.html">$nearSphere</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/box.html">$box</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/center.html">$center</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/centerSphere.html">$centerSphere</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/geometry.html">$geometry</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/maxDistance.html">$maxDistance</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/minDistance.html">$minDistance</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/polygon.html">$polygon</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/uniqueDocs.html">$uniqueDocs</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/query-array.html">Array Query Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/all.html">$all</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/elemMatch.html">$elemMatch (query)</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/size.html">$size</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/query-bitwise.html">Bitwise Query Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/bitsAllClear.html">$bitsAllClear</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/bitsAllSet.html">$bitsAllSet</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/bitsAnyClear.html">$bitsAnyClear</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/query/bitsAnySet.html">$bitsAnySet</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/query/comment.html">$comment</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/projection.html">Projection Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/projection/positional.html">$ (projection)</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/projection/elemMatch.html">$elemMatch (projection)</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/projection/meta.html">$meta</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/projection/slice.html">$slice (projection)</a></li></ul></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/operator/update.html">Update Operators</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/operator/update-field.html">Field Update Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/currentDate.html">$currentDate</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/inc.html">$inc</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/min.html">$min</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/max.html">$max</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/mul.html">$mul</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/rename.html">$rename</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/set.html">$set</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/setOnInsert.html">$setOnInsert</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/unset.html">$unset</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/update-array.html">Array Update Operators</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/positional.html">$ (update)</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/positional-all.html">$[]</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/positional-filtered.html">$[&lt;identifier&gt;]</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/addToSet.html">$addToSet</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/pop.html">$pop</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/pull.html">$pull</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/push.html">$push</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/pullAll.html">$pullAll</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/each.html">$each</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/position.html">$position</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/slice.html">$slice</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/sort.html">$sort</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/update-bitwise.html">Bitwise Update Operator</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/operator/update/bit.html">$bit</a></li></ul></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/operator/aggregation-pipeline.html">Aggregation Pipeline Stages</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/addFields.html">$addFields (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/bucket.html">$bucket (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/bucketAuto.html">$bucketAuto (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/collStats.html">$collStats (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/count.html">$count (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/currentOp.html">$currentOp (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/facet.html">$facet (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/geoNear.html">$geoNear (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/graphLookup.html">$graphLookup (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/group.html">$group (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/indexStats.html">$indexStats (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/limit.html">$limit (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/listLocalSessions.html">$listLocalSessions</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/listSessions.html">$listSessions</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/lookup.html">$lookup (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/match.html">$match (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/merge.html">$merge (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/out.html">$out (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/planCacheStats.html">$planCacheStats</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/project.html">$project (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/redact.html">$redact (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/replaceRoot.html">$replaceRoot (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/replaceWith.html">$replaceWith (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/sample.html">$sample (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/set.html">$set (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/skip.html">$skip (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/sort.html">$sort (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/sortByCount.html">$sortByCount (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/unset.html">$unset (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/unwind.html">$unwind (aggregation)</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/operator/aggregation.html">Aggregation Pipeline Operators</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/abs.html">$abs (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/acos.html">$acos (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/acosh.html">$acosh (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/add.html">$add (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/addToSet.html">$addToSet (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/allElementsTrue.html">$allElementsTrue (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/and.html">$and (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/anyElementTrue.html">$anyElementTrue (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/arrayElemAt.html">$arrayElemAt (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/arrayToObject.html">$arrayToObject (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/asin.html">$asin (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/asinh.html">$asinh (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/atan.html">$atan (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/atan2.html">$atan2 (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/atanh.html">$atanh (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/avg.html">$avg (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/ceil.html">$ceil (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/cmp.html">$cmp (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/concat.html">$concat (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/concatArrays.html">$concatArrays (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/cond.html">$cond (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/convert.html">$convert (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/cos.html">$cos (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/dateFromParts.html">$dateFromParts (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/dateToParts.html">$dateToParts (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/dateFromString.html">$dateFromString (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/dateToString.html">$dateToString (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/dayOfMonth.html">$dayOfMonth (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/dayOfWeek.html">$dayOfWeek (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/dayOfYear.html">$dayOfYear (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/degreesToRadians.html">$degreesToRadians (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/divide.html">$divide (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/eq.html">$eq (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/exp.html">$exp (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/filter.html">$filter (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/first.html">$first (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/floor.html">$floor (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/gt.html">$gt (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/gte.html">$gte (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/hour.html">$hour (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/ifNull.html">$ifNull (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/in.html">$in (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/indexOfArray.html">$indexOfArray (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/indexOfBytes.html">$indexOfBytes (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/indexOfCP.html">$indexOfCP (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/isArray.html">$isArray (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/isoDayOfWeek.html">$isoDayOfWeek (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/isoWeek.html">$isoWeek (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/isoWeekYear.html">$isoWeekYear (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/last.html">$last (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/let.html">$let (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/literal.html">$literal (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/ln.html">$ln (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/log.html">$log (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/log10.html">$log10 (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/lt.html">$lt (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/lte.html">$lte (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/ltrim.html">$ltrim (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/map.html">$map (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/max.html">$max (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/mergeObjects.html">$mergeObjects (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/meta.html">$meta (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/min.html">$min (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/millisecond.html">$millisecond (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/minute.html">$minute (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/mod.html">$mod (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/month.html">$month (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/multiply.html">$multiply (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/ne.html">$ne (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/not.html">$not (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/objectToArray.html">$objectToArray (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/or.html">$or (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/pow.html">$pow (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/push.html">$push (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/radiansToDegrees.html">$radiansToDegrees (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/range.html">$range (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/reduce.html">$reduce (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/regexFind.html">$regexFind (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/regexFindAll.html">$regexFindAll (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/regexMatch.html">$regexMatch (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/reverseArray.html">$reverseArray (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/round.html">$round (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/rtrim.html">$rtrim (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/second.html">$second (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/setDifference.html">$setDifference (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/setEquals.html">$setEquals (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/setIntersection.html">$setIntersection (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/setIsSubset.html">$setIsSubset (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/setUnion.html">$setUnion (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/size.html">$size (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/sin.html">$sin (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/slice.html">$slice (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/split.html">$split (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/sqrt.html">$sqrt (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/stdDevPop.html">$stdDevPop (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/stdDevSamp.html">$stdDevSamp (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/strcasecmp.html">$strcasecmp (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/strLenBytes.html">$strLenBytes (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/strLenCP.html">$strLenCP (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/substr.html">$substr (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/substrBytes.html">$substrBytes (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/substrCP.html">$substrCP (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/subtract.html">$subtract (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/sum.html">$sum (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/switch.html">$switch (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/tan.html">$tan (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toBool.html">$toBool (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toDate.html">$toDate (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toDecimal.html">$toDecimal (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toDouble.html">$toDouble(aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toInt.html">$toInt (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toLong.html">$toLong (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toObjectId.html">$toObjectId (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toString.html">$toString (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toLower.html">$toLower (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/toUpper.html">$toUpper (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/trim.html">$trim (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/trunc.html">$trunc (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/type.html">$type (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/week.html">$week (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/year.html">$year (aggregation)</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/aggregation/zip.html">$zip (aggregation)</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/operator/query-modifier.html">Query Modifiers</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/comment.html">$comment</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/explain.html">$explain</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/hint.html">$hint</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/max.html">$max</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/maxTimeMS.html">$maxTimeMS</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/min.html">$min</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/orderby.html">$orderby</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/query.html">$query</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/returnKey.html">$returnKey</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/showDiskLoc.html">$showDiskLoc</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/operator/meta/natural.html">$natural</a></li></ul></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/command.html">Database Commands</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-aggregation.html">Aggregation Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/aggregate.html">aggregate</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/count.html">count</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/distinct.html">distinct</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/mapReduce.html">mapReduce</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-geospatial.html">Geospatial Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/geoSearch.html">geoSearch</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-crud.html">Query and Write Operation Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/delete.html">delete</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/find.html">find</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/findAndModify.html">findAndModify</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/getLastError.html">getLastError</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/getMore.html">getMore</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/insert.html">insert</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/resetError.html">resetError</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/update.html">update</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-plan-cache.html">Query Plan Cache Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/planCacheClear.html">planCacheClear</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/planCacheClearFilters.html">planCacheClearFilters</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/planCacheListFilters.html">planCacheListFilters</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/planCacheListPlans.html">planCacheListPlans</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/planCacheListQueryShapes.html">planCacheListQueryShapes</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/planCacheSetFilter.html">planCacheSetFilter</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-authentication.html">Authentication Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/authenticate.html">authenticate</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/getnonce.html">getnonce</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/logout.html">logout</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-user-management.html">User Management Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/createUser.html">createUser</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dropAllUsersFromDatabase.html">dropAllUsersFromDatabase</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dropUser.html">dropUser</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/grantRolesToUser.html">grantRolesToUser</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/revokeRolesFromUser.html">revokeRolesFromUser</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/updateUser.html">updateUser</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/usersInfo.html">usersInfo</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-role-management.html">Role Management Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/createRole.html">createRole</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dropRole.html">dropRole</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dropAllRolesFromDatabase.html">dropAllRolesFromDatabase</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/grantPrivilegesToRole.html">grantPrivilegesToRole</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/grantRolesToRole.html">grantRolesToRole</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/invalidateUserCache.html">invalidateUserCache</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/revokePrivilegesFromRole.html">revokePrivilegesFromRole</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/revokeRolesFromRole.html">revokeRolesFromRole</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/rolesInfo.html">rolesInfo</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/updateRole.html">updateRole</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-replication.html">Replication Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/applyOps.html">applyOps</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/isMaster.html">isMaster</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetAbortPrimaryCatchUp.html">replSetAbortPrimaryCatchUp</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetFreeze.html">replSetFreeze</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetGetConfig.html">replSetGetConfig</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetGetStatus.html">replSetGetStatus</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetInitiate.html">replSetInitiate</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetMaintenance.html">replSetMaintenance</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetReconfig.html">replSetReconfig</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetResizeOplog.html">replSetResizeOplog</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetStepDown.html">replSetStepDown</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/replSetSyncFrom.html">replSetSyncFrom</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-sharding.html">Sharding Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/addShard.html">addShard</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/addShardToZone.html">addShardToZone</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/balancerStart.html">balancerStart</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/balancerStatus.html">balancerStatus</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/balancerStop.html">balancerStop</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/checkShardingIndex.html">checkShardingIndex</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/clearJumboFlag.html">clearJumboFlag</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/cleanupOrphaned.html">cleanupOrphaned</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/enableSharding.html">enableSharding</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/flushRouterConfig.html">flushRouterConfig</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/getShardMap.html">getShardMap</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/getShardVersion.html">getShardVersion</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/isdbgrid.html">isdbgrid</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/listShards.html">listShards</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/medianKey.html">medianKey</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/moveChunk.html">moveChunk</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/movePrimary.html">movePrimary</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/mergeChunks.html">mergeChunks</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/removeShard.html">removeShard</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/removeShardFromZone.html">removeShardFromZone</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/setShardVersion.html">setShardVersion</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/shardCollection.html">shardCollection</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/shardingState.html">shardingState</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/split.html">split</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/splitChunk.html">splitChunk</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/splitVector.html">splitVector</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/unsetSharding.html">unsetSharding</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/updateZoneKeyRange.html">updateZoneKeyRange</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-sessions.html">Sessions Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/abortTransaction.html">abortTransaction</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/commitTransaction.html">commitTransaction</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/endSessions.html">endSessions</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/killAllSessions.html">killAllSessions</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/killAllSessionsByPattern.html">killAllSessionsByPattern</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/killSessions.html">killSessions</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/refreshSessions.html">refreshSessions</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/startSession.html">startSession</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-administration.html">Administration Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/clean.html">clean</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/cloneCollection.html">cloneCollection</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/cloneCollectionAsCapped.html">cloneCollectionAsCapped</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/collMod.html">collMod</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/compact.html">compact</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/connPoolSync.html">connPoolSync</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/convertToCapped.html">convertToCapped</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/create.html">create</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/createIndexes.html">createIndexes</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/currentOp.html">currentOp</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/drop.html">drop</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dropDatabase.html">dropDatabase</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dropConnections.html">dropConnections</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dropIndexes.html">dropIndexes</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/filemd5.html">filemd5</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/fsync.html">fsync</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/fsyncUnlock.html">fsyncUnlock</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/getParameter.html">getParameter</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/killCursors.html">killCursors</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/killOp.html">killOp</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/listCollections.html">listCollections</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/listDatabases.html">listDatabases</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/listIndexes.html">listIndexes</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/logRotate.html">logRotate</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/reIndex.html">reIndex</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/renameCollection.html">renameCollection</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/setFeatureCompatibilityVersion.html">setFeatureCompatibilityVersion</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/setParameter.html">setParameter</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/shutdown.html">shutdown</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-diagnostic.html">Diagnostic Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/availableQueryOptions.html">availableQueryOptions</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/buildInfo.html">buildInfo</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/collStats.html">collStats</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/connPoolStats.html">connPoolStats</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/connectionStatus.html">connectionStatus</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/cursorInfo.html">cursorInfo</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dataSize.html">dataSize</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dbHash.html">dbHash</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/dbStats.html">dbStats</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/diagLogging.html">diagLogging</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/driverOIDTest.html">driverOIDTest</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/explain.html">explain</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/features.html">features</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/getCmdLineOpts.html">getCmdLineOpts</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/getLog.html">getLog</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/hostInfo.html">hostInfo</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/isSelf.html">isSelf</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/listCommands.html">listCommands</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/netstat.html">netstat</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/ping.html">ping</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/profile.html">profile</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/serverStatus.html">serverStatus</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/shardConnPoolStats.html">shardConnPoolStats</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/top.html">top</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/validate.html">validate</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/whatsmyuri.html">whatsmyuri</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-free-monitoring.html">Free Monitoring Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/getFreeMonitoringStatus.html">getFreeMonitoringStatus</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/command/setFreeMonitoring.html">setFreeMonitoring</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/command/nav-auditing.html">System Events Auditing Commands</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/command/logApplicationMessage.html">logApplicationMessage</a></li></ul></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/method.html"><code class="docutils literal"><span class="pre">mongo</span></code> Shell Methods</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-collection.html">Collection Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.aggregate.html">db.collection.aggregate()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.bulkWrite.html">db.collection.bulkWrite()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.copyTo.html">db.collection.copyTo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.count.html">db.collection.count()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.countDocuments.html">db.collection.countDocuments()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.estimatedDocumentCount.html">db.collection.estimatedDocumentCount()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.createIndex.html">db.collection.createIndex()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.createIndexes.html">db.collection.createIndexes()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.dataSize.html">db.collection.dataSize()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.deleteOne.html">db.collection.deleteOne()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.deleteMany.html">db.collection.deleteMany()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.distinct.html">db.collection.distinct()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.drop.html">db.collection.drop()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.dropIndex.html">db.collection.dropIndex()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.dropIndexes.html">db.collection.dropIndexes()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.ensureIndex.html">db.collection.ensureIndex()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.explain.html">db.collection.explain()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.find.html">db.collection.find()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.findAndModify.html">db.collection.findAndModify()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.findOne.html">db.collection.findOne()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.findOneAndDelete.html">db.collection.findOneAndDelete()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.findOneAndReplace.html">db.collection.findOneAndReplace()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.findOneAndUpdate.html">db.collection.findOneAndUpdate()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.getIndexes.html">db.collection.getIndexes()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.getShardDistribution.html">db.collection.getShardDistribution()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.getShardVersion.html">db.collection.getShardVersion()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.insert.html">db.collection.insert()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.insertOne.html">db.collection.insertOne()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.insertMany.html">db.collection.insertMany()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.isCapped.html">db.collection.isCapped()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.latencyStats.html">db.collection.latencyStats()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.mapReduce.html">db.collection.mapReduce()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.reIndex.html">db.collection.reIndex()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.remove.html">db.collection.remove()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.renameCollection.html">db.collection.renameCollection()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.replaceOne.html">db.collection.replaceOne()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.save.html">db.collection.save()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.stats.html">db.collection.stats()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.storageSize.html">db.collection.storageSize()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.totalIndexSize.html">db.collection.totalIndexSize()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.totalSize.html">db.collection.totalSize()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.update.html">db.collection.update()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.updateOne.html">db.collection.updateOne()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.updateMany.html">db.collection.updateMany()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.watch.html">db.collection.watch()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.validate.html">db.collection.validate()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-cursor.html">Cursor Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.addOption.html">cursor.addOption()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.allowPartialResults.html">cursor.allowPartialResults()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.batchSize.html">cursor.batchSize()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.close.html">cursor.close()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.isClosed.html">cursor.isClosed()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.collation.html">cursor.collation()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.comment.html">cursor.comment()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.count.html">cursor.count()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.explain.html">cursor.explain()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.forEach.html">cursor.forEach()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.hasNext.html">cursor.hasNext()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.hint.html">cursor.hint()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.isExhausted.html">cursor.isExhausted()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.itcount.html">cursor.itcount()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.limit.html">cursor.limit()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.map.html">cursor.map()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.max.html">cursor.max()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.maxTimeMS.html">cursor.maxTimeMS()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.min.html">cursor.min()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.next.html">cursor.next()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.noCursorTimeout.html">cursor.noCursorTimeout()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.objsLeftInBatch.html">cursor.objsLeftInBatch()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.pretty.html">cursor.pretty()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.readConcern.html">cursor.readConcern()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.readPref.html">cursor.readPref()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.returnKey.html">cursor.returnKey()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.showRecordId.html">cursor.showRecordId()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.size.html">cursor.size()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.skip.html">cursor.skip()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.sort.html">cursor.sort()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.tailable.html">cursor.tailable()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cursor.toArray.html">cursor.toArray()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-database.html">Database Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.adminCommand.html">db.adminCommand()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.aggregate.html">db.aggregate()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.cloneCollection.html">db.cloneCollection()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.cloneDatabase.html">db.cloneDatabase()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.commandHelp.html">db.commandHelp()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.copyDatabase.html">db.copyDatabase()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.createCollection.html">db.createCollection()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.createView.html">db.createView()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.currentOp.html">db.currentOp()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.dropDatabase.html">db.dropDatabase()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.eval.html">db.eval()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.fsyncLock.html">db.fsyncLock()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.fsyncUnlock.html">db.fsyncUnlock()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getCollection.html">db.getCollection()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getCollectionInfos.html">db.getCollectionInfos()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getCollectionNames.html">db.getCollectionNames()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getLastError.html">db.getLastError()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getLastErrorObj.html">db.getLastErrorObj()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getLogComponents.html">db.getLogComponents()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getMongo.html">db.getMongo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getName.html">db.getName()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getProfilingLevel.html">db.getProfilingLevel()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getProfilingStatus.html">db.getProfilingStatus()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getReplicationInfo.html">db.getReplicationInfo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getSiblingDB.html">db.getSiblingDB()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.help.html">db.help()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.hostInfo.html">db.hostInfo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.isMaster.html">db.isMaster()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.killOp.html">db.killOp()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.listCommands.html">db.listCommands()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.logout.html">db.logout()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.printCollectionStats.html">db.printCollectionStats()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.printReplicationInfo.html">db.printReplicationInfo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.printShardingStatus.html">db.printShardingStatus()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.printSlaveReplicationInfo.html">db.printSlaveReplicationInfo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.resetError.html">db.resetError()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.runCommand.html">db.runCommand()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.serverBuildInfo.html">db.serverBuildInfo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.serverCmdLineOpts.html">db.serverCmdLineOpts()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.serverStatus.html">db.serverStatus()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.setLogLevel.html">db.setLogLevel()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.setProfilingLevel.html">db.setProfilingLevel()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.shutdownServer.html">db.shutdownServer()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.stats.html">db.stats()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.version.html">db.version()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.watch.html">db.watch()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-plan-cache.html">Query Plan Cache Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.getPlanCache.html">db.collection.getPlanCache()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/PlanCache.clear.html">PlanCache.clear()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/PlanCache.clearPlansByQuery.html">PlanCache.clearPlansByQuery()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/PlanCache.getPlansByQuery.html">PlanCache.getPlansByQuery()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/PlanCache.help.html">PlanCache.help()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/PlanCache.listQueryShapes.html">PlanCache.listQueryShapes()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-bulk.html">Bulk Operation Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.initializeOrderedBulkOp.html">db.collection.initializeOrderedBulkOp()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.collection.initializeUnorderedBulkOp.html">db.collection.initializeUnorderedBulkOp()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.html">Bulk()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.execute.html">Bulk.execute()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.html">Bulk.find()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.arrayFilters.html">Bulk.find.arrayFilters()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.collation.html">Bulk.find.collation()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.hint.html">Bulk.find.hint()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.remove.html">Bulk.find.remove()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.removeOne.html">Bulk.find.removeOne()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.replaceOne.html">Bulk.find.replaceOne()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.updateOne.html">Bulk.find.updateOne()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.update.html">Bulk.find.update()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.find.upsert.html">Bulk.find.upsert()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.getOperations.html">Bulk.getOperations()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.insert.html">Bulk.insert()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.tojson.html">Bulk.tojson()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Bulk.toString.html">Bulk.toString()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-user-management.html">User Management Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.auth.html">db.auth()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.changeUserPassword.html">db.changeUserPassword()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.createUser.html">db.createUser()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.dropUser.html">db.dropUser()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.dropAllUsers.html">db.dropAllUsers()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getUser.html">db.getUser()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getUsers.html">db.getUsers()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.grantRolesToUser.html">db.grantRolesToUser()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.removeUser.html">db.removeUser()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.revokeRolesFromUser.html">db.revokeRolesFromUser()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.updateUser.html">db.updateUser()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/passwordPrompt.html">passwordPrompt()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-role-management.html">Role Management Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.createRole.html">db.createRole()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.dropRole.html">db.dropRole()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.dropAllRoles.html">db.dropAllRoles()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getRole.html">db.getRole()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getRoles.html">db.getRoles()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.grantPrivilegesToRole.html">db.grantPrivilegesToRole()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.revokePrivilegesFromRole.html">db.revokePrivilegesFromRole()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.grantRolesToRole.html">db.grantRolesToRole()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.revokeRolesFromRole.html">db.revokeRolesFromRole()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.updateRole.html">db.updateRole()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-replication.html">Replication Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.add.html">rs.add()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.addArb.html">rs.addArb()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.conf.html">rs.conf()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.freeze.html">rs.freeze()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.help.html">rs.help()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.initiate.html">rs.initiate()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.printReplicationInfo.html">rs.printReplicationInfo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.printSlaveReplicationInfo.html">rs.printSlaveReplicationInfo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.reconfig.html">rs.reconfig()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.remove.html">rs.remove()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.slaveOk.html">rs.slaveOk()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.status.html">rs.status()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.stepDown.html">rs.stepDown()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rs.syncFrom.html">rs.syncFrom()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-sharding.html">Sharding Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.addShard.html">sh.addShard()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.addShardTag.html">sh.addShardTag()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.addShardToZone.html">sh.addShardToZone()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.addTagRange.html">sh.addTagRange()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.disableBalancing.html">sh.disableBalancing()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.enableBalancing.html">sh.enableBalancing()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.disableAutoSplit.html">sh.disableAutoSplit</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.enableAutoSplit.html">sh.enableAutoSplit</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.enableSharding.html">sh.enableSharding()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.getBalancerHost.html">sh.getBalancerHost()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.getBalancerState.html">sh.getBalancerState()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.removeTagRange.html">sh.removeTagRange()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.removeRangeFromZone.html">sh.removeRangeFromZone()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.help.html">sh.help()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.isBalancerRunning.html">sh.isBalancerRunning()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.moveChunk.html">sh.moveChunk()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.removeShardTag.html">sh.removeShardTag()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.removeShardFromZone.html">sh.removeShardFromZone()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.setBalancerState.html">sh.setBalancerState()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.shardCollection.html">sh.shardCollection()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.splitAt.html">sh.splitAt()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.splitFind.html">sh.splitFind()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.startBalancer.html">sh.startBalancer()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.status.html">sh.status()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.stopBalancer.html">sh.stopBalancer()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.waitForBalancer.html">sh.waitForBalancer()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.waitForBalancerOff.html">sh.waitForBalancerOff()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.waitForPingChange.html">sh.waitForPingChange()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sh.updateZoneKeyRange.html">sh.updateZoneKeyRange()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/convertShardKeyToHashed.html">convertShardKeyToHashed</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-free-monitoring.html">Free Monitoring Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.disableFreeMonitoring.html">db.disableFreeMonitoring()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.enableFreeMonitoring.html">db.enableFreeMonitoring()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/db.getFreeMonitoringStatus.html">db.getFreeMonitoringStatus</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-constructor.html">Object Constructors and Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/BulkWriteResult.html">BulkWriteResult()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Date.html">Date()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/ObjectId.html">ObjectId</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/ObjectId.getTimestamp.html">ObjectId.getTimestamp()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/ObjectId.toString.html">ObjectId.toString()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/ObjectId.valueOf.html">ObjectId.valueOf()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/UUID.html">UUID()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/WriteResult.html">WriteResult()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/WriteResult.hasWriteError.html">WriteResult.hasWriteError()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/WriteResult.hasWriteConcernError.html">WriteResult.hasWriteConcernError()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-connection.html">Connection Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/connect.html">connect()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.html">Mongo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.getDB.html">Mongo.getDB()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.getReadPrefMode.html">Mongo.getReadPrefMode()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.getReadPrefTagSet.html">Mongo.getReadPrefTagSet()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.isCausalConsistency.html">Mongo.isCausalConsistency()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.setCausalConsistency.html">Mongo.setCausalConsistency()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.setReadPref.html">Mongo.setReadPref()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.setSlaveOk.html">Mongo.setSlaveOk()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.startSession.html">Mongo.startSession()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Mongo.watch.html">Mongo.watch()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/Session.html">Session</a><ul><li class="toctree-l5"><a class="reference internal" href="../reference/method/Session.abortTransaction.html">Session.abortTransaction()</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/method/Session.commitTransaction.html">Session.commitTransaction()</a></li><li class="toctree-l5"><a class="reference internal" href="../reference/method/Session.startTransaction.html">Session.startTransaction()</a></li></ul></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/SessionOptions.html">SessionOptions</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-native.html">Native Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/cat.html">cat()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/cd.html">cd()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/copyDbpath.html">copyDbpath()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/getHostName.html">getHostName()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/getMemInfo.html">getMemInfo()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/hostname.html">hostname()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/isInteractive.html">isInteractive()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/listFiles.html">listFiles()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/load.html">load()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/ls.html">ls()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/md5sumFile.html">md5sumFile()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/mkdir.html">mkdir()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/pwd.html">pwd()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/quit.html">quit()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/removeFile.html">removeFile()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/resetDbpath.html">resetDbpath()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/sleep.html">sleep()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/setVerboseShell.html">setVerboseShell()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/version.html">version()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/isWindows.html">_isWindows()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/rand.html">_rand()</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="../reference/method/js-client-side-field-level-encryption.html">Client-Side Field Level Encryption Methods</a><ul><li class="toctree-l4"><a class="reference internal" href="../reference/method/getKeyVault.html">getKeyVault()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/KeyVault.createKey.html">KeyVault.createKey()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/KeyVault.deleteKey.html">KeyVault.deleteKey()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/KeyVault.getKey.html">KeyVault.getKey()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/KeyVault.getKeys.html">KeyVault.getKeys()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/KeyVault.addKeyAlternateName.html">KeyVault.addKeyAlternateName()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/KeyVault.removeKeyAlternateName.html">KeyVault.removeKeyAlternateName()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/KeyVault.getKeyByAltName.html">KeyVault.getKeyByAltName()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/getClientEncryption.html">getClientEncryption()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/ClientEncryption.encrypt.html">ClientEncryption.encrypt()</a></li><li class="toctree-l4"><a class="reference internal" href="../reference/method/ClientEncryption.decrypt.html">ClientEncryption.decrypt()</a></li></ul></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/program.html">MongoDB Package Components</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongod.html"><code class="docutils literal"><span class="pre">mongod</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongos.html"><code class="docutils literal"><span class="pre">mongos</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongo.html"><code class="docutils literal"><span class="pre">mongo</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongod.exe.html"><code class="docutils literal"><span class="pre">mongod.exe</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongos.exe.html"><code class="docutils literal"><span class="pre">mongos.exe</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongodump.html"><code class="docutils literal"><span class="pre">mongodump</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongorestore.html"><code class="docutils literal"><span class="pre">mongorestore</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/bsondump.html"><code class="docutils literal"><span class="pre">bsondump</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongoimport.html"><code class="docutils literal"><span class="pre">mongoimport</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongoexport.html"><code class="docutils literal"><span class="pre">mongoexport</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongostat.html"><code class="docutils literal"><span class="pre">mongostat</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongotop.html"><code class="docutils literal"><span class="pre">mongotop</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongoreplay.html"><code class="docutils literal"><span class="pre">mongoreplay</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongoldap.html"><code class="docutils literal"><span class="pre">mongoldap</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/mongofiles.html"><code class="docutils literal"><span class="pre">mongofiles</span></code></a></li><li class="toctree-l3"><a class="reference internal" href="../reference/program/install_compass.html"><code class="docutils literal"><span class="pre">install_compass</span></code></a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/configuration-options.html">Configuration File Options</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/expansion-directives.html">Externally Sourced Configuration File Values</a></li><li class="toctree-l3"><a class="reference internal" href="../tutorial/convert-command-line-options-to-yaml.html">Convert Command-Line Options to YAML</a></li><li class="toctree-l3"><a class="reference internal" href="../reference/configuration-file-settings-command-line-options-mapping.html">Configuration File Settings and Command-Line Options Mapping</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/parameters.html">MongoDB Server Parameters</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/limits.html">MongoDB Limits and Thresholds</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/explain-results.html">Explain Results</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/system-collections.html">System Collections</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/connection-string.html">Connection String URI Format</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/collation.html">Collation</a><ul><li class="toctree-l3"><a class="reference internal" href="../reference/collation-locales-defaults.html">Collation Locales and Default Parameters</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="../reference/mongodb-wire-protocol.html">MongoDB Wire Protocol</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/log-messages.html">Log Messages</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/exit-codes.html">Exit Codes and Statuses</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/glossary.html">Glossary</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/default-mongodb-port.html">Default MongoDB Port</a></li><li class="toctree-l2"><a class="reference internal" href="../reference/server-sessions.html">Server Sessions</a></li></ul></li><li class="toctree-l1 current"><a class="reference internal" href="../release-notes.html">Release Notes</a><ul class="current"><li class="toctree-l2"><a class="reference internal" href="4.2.html">Release Notes for MongoDB 4.2</a><ul><li class="toctree-l3"><a class="reference internal" href="4.2-compatibility.html">Compatibility Changes in MongoDB 4.2</a></li><li class="toctree-l3"><a class="reference internal" href="4.2-upgrade-standalone.html">Upgrade a Standalone to 4.2</a></li><li class="toctree-l3"><a class="reference internal" href="4.2-upgrade-replica-set.html">Upgrade a Replica Set to 4.2</a></li><li class="toctree-l3"><a class="reference internal" href="4.2-upgrade-sharded-cluster.html">Upgrade a Sharded Cluster to 4.2</a></li><li class="toctree-l3"><a class="reference internal" href="4.2-downgrade.html">Downgrade 4.2 to 4.0</a><ul><li class="toctree-l4"><a class="reference internal" href="4.2-downgrade-standalone.html">Downgrade 4.2 Standalone to 4.0</a></li><li class="toctree-l4"><a class="reference internal" href="4.2-downgrade-replica-set.html">Downgrade 4.2 Replica Set to 4.0</a></li><li class="toctree-l4"><a class="reference internal" href="4.2-downgrade-sharded-cluster.html">Downgrade 4.2 Sharded Cluster to 4.0</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="4.2-changelog.html">4.2 Changelog</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="4.0.html">Release Notes for MongoDB 4.0</a><ul><li class="toctree-l3"><a class="reference internal" href="4.0-compatibility.html">Compatibility Changes in MongoDB 4.0</a></li><li class="toctree-l3"><a class="reference internal" href="4.0-upgrade-standalone.html">Upgrade a Standalone to 4.0</a></li><li class="toctree-l3"><a class="reference internal" href="4.0-upgrade-replica-set.html">Upgrade a Replica Set to 4.0</a></li><li class="toctree-l3"><a class="reference internal" href="4.0-upgrade-sharded-cluster.html">Upgrade a Sharded Cluster to 4.0</a></li><li class="toctree-l3"><a class="reference internal" href="4.0-downgrade-standalone.html">Downgrade 4.0 Standalone to 3.6</a></li><li class="toctree-l3"><a class="reference internal" href="4.0-downgrade-replica-set.html">Downgrade 4.0 Replica Set to 3.6</a></li><li class="toctree-l3"><a class="reference internal" href="4.0-downgrade-sharded-cluster.html">Downgrade 4.0 Sharded Cluster to 3.6</a></li><li class="toctree-l3"><a class="reference internal" href="4.0-changelog.html">4.0 Changelog</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="3.6.html">Release Notes for MongoDB 3.6</a><ul><li class="toctree-l3"><a class="reference internal" href="3.6-changelog.html">3.6 Changelog</a></li><li class="toctree-l3"><a class="reference internal" href="3.6-compatibility.html">Compatibility Changes in MongoDB 3.6</a></li><li class="toctree-l3"><a class="reference internal" href="3.6-upgrade-standalone.html">Upgrade a Standalone to 3.6</a></li><li class="toctree-l3"><a class="reference internal" href="3.6-upgrade-replica-set.html">Upgrade a Replica Set to 3.6</a></li><li class="toctree-l3"><a class="reference internal" href="3.6-upgrade-sharded-cluster.html">Upgrade a Sharded Cluster to 3.6</a></li><li class="toctree-l3"><a class="reference internal" href="3.6-downgrade-standalone.html">Downgrade 3.6 Standalone to 3.4</a></li><li class="toctree-l3"><a class="reference internal" href="3.6-downgrade-replica-set.html">Downgrade 3.6 Replica Set to 3.4</a></li><li class="toctree-l3"><a class="reference internal" href="3.6-downgrade-sharded-cluster.html">Downgrade 3.6 Sharded Cluster to 3.4</a></li></ul></li><li class="toctree-l2 current"><a class="reference internal current" href="">Release Notes for MongoDB 3.4</a><ul><li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html">3.4 Changelog</a></li><li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html">Compatibility Changes in MongoDB 3.4</a></li><li class="toctree-l3"><a class="reference internal" href="3.4-upgrade-standalone.html">Upgrade a Standalone to 3.4</a></li><li class="toctree-l3"><a class="reference internal" href="3.4-upgrade-replica-set.html">Upgrade a Replica Set to 3.4</a></li><li class="toctree-l3"><a class="reference internal" href="3.4-upgrade-sharded-cluster.html">Upgrade a Sharded Cluster to 3.4</a></li><li class="toctree-l3"><a class="reference internal" href="3.4-downgrade.html">Downgrade MongoDB 3.4 to 3.2</a><ul><li class="toctree-l4"><a class="reference internal" href="3.4-downgrade-standalone.html">Downgrade 3.4 Standalone to 3.2</a></li><li class="toctree-l4"><a class="reference internal" href="3.4-downgrade-replica-set.html">Downgrade 3.4 Replica Set to 3.2</a></li><li class="toctree-l4"><a class="reference internal" href="3.4-downgrade-sharded-cluster.html">Downgrade 3.4 Sharded Cluster to 3.2</a></li></ul></li></ul></li><li class="toctree-l2"><a class="reference internal" href="3.2.html">Release Notes for MongoDB 3.2</a><ul><li class="toctree-l3"><a class="reference internal" href="3.2-changelog.html">3.2 Changelog</a></li><li class="toctree-l3"><a class="reference internal" href="3.2-compatibility.html">Compatibility Changes in MongoDB 3.2</a><ul><li class="toctree-l4"><a class="reference internal" href="3.2-javascript.html">JavaScript Changes in MongoDB 3.2</a></li></ul></li><li class="toctree-l3"><a class="reference internal" href="3.2-upgrade.html">Upgrade MongoDB to 3.2</a></li><li class="toctree-l3"><a class="reference internal" href="3.2-downgrade.html">Downgrade MongoDB from 3.2</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="3.0.html">Release Notes for MongoDB 3.0</a><ul><li class="toctree-l3"><a class="reference internal" href="3.0-changelog.html">3.0 Changelog</a></li><li class="toctree-l3"><a class="reference internal" href="3.0-compatibility.html">Compatibility Changes in MongoDB 3.0</a></li><li class="toctree-l3"><a class="reference internal" href="3.0-upgrade.html">Upgrade MongoDB to 3.0</a></li><li class="toctree-l3"><a class="reference internal" href="3.0-scram.html">Upgrade to SCRAM</a></li><li class="toctree-l3"><a class="reference internal" href="3.0-downgrade.html">Downgrade MongoDB from 3.0</a></li></ul></li><li class="toctree-l2"><a class="reference internal" href="2.6.html">Release Notes for MongoDB 2.6</a><ul><li class="toctree-l3"><a class="reference internal" href="2.6-changelog.html">2.6 Changelog</a></li><li class="toctree-l3"><a class="reference internal" href="2.6-compatibility.html">Compatibility Changes in MongoDB 2.6</a></li><li class="toctree-l3"><a class="reference internal" href="2.6-upgrade.html">Upgrade MongoDB to 2.6</a></li><li class="toctree-l3"><a class="reference internal" href="2.6-upgrade-authorization.html">Upgrade User Authorization Data to 2.6 Format</a></li><li class="toctree-l3"><a class="reference internal" href="2.6-downgrade.html">Downgrade MongoDB from 2.6</a></li></ul></li><li 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                  <div class="section" id="release-notes-for-mongodb-3-4">
<h1>Release Notes for MongoDB 3.4<a class="headerlink" href="#release-notes-for-mongodb-3-4" title="Permalink to this headline">¶</a></h1>
<div class="contents twocols local topic" id="on-this-page">
<p class="topic-title first">On this page</p>
<ul class="simple">
<li><a class="reference internal" href="#minor-releases" id="id27">Minor Releases</a></li>
<li><a class="reference internal" href="#sharded-cluster" id="id28">Sharded Cluster</a></li>
<li><a class="reference internal" href="#replica-set" id="id29">Replica Set</a></li>
<li><a class="reference internal" href="#decimal-type" id="id30">Decimal Type</a></li>
<li><a class="reference internal" href="#aggregation" id="id31">Aggregation</a></li>
<li><a class="reference internal" href="#collation-and-case-insensitive-indexes" id="id32">Collation and Case-Insensitive Indexes</a></li>
<li><a class="reference internal" href="#views" id="id33">Views</a></li>
<li><a class="reference internal" href="#security-enhancement" id="id34">Security Enhancement</a></li>
<li><a class="reference internal" href="#mongodb-tools" id="id35">MongoDB Tools</a></li>
<li><a class="reference internal" href="#general-enhancements" id="id36">General Enhancements</a></li>
<li><a class="reference internal" href="#platform-support" id="id37">Platform Support</a></li>
<li><a class="reference internal" href="#mongodb-enterprise-features" id="id38">MongoDB Enterprise Features</a></li>
<li><a class="reference internal" href="#changes-affecting-compatibility" id="id39">Changes Affecting Compatibility</a></li>
<li><a class="reference internal" href="#upgrade-procedures" id="id40">Upgrade Procedures</a></li>
<li><a class="reference internal" href="#download" id="id41">Download</a></li>
<li><a class="reference internal" href="#known-issues-in-3-4-0" id="id42">Known Issues in 3.4.0</a></li>
</ul>
</div>
<div class="admonition-mongodb-3-4-released-nov-29-2016 admonition">
<p class="first admonition-title">MongoDB 3.4 Released Nov 29, 2016</p>
<p>MongoDB 3.4 is now available. Key features include linearizable read
concerns, views, and collation.</p>
<p class="last">OpsManager 3.4 is also available. See the <a class="reference external" href="http://docs.opsmanager.mongodb.com/current/">Ops Manager documentation</a> and the <a class="reference external" href="http://docs.opsmanager.mongodb.com/current/release-notes/application/">Ops Manager
release notes</a>
for more information.</p>
</div>
<div class="section" id="minor-releases">
<h2>Minor Releases<a class="headerlink" href="#minor-releases" title="Permalink to this headline">¶</a></h2>
<div class="toctree-wrapper hidden compound">
<ul>
<li class="toctree-l1"><a class="reference internal" href="3.4-changelog.html">3.4 Changelog</a><ul>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id1">3.4.24 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#security">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#sharding">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#replication">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#query">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#build-and-packaging">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#internals">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id3">3.4.23 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id5">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id6">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id7">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#storage">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#operations">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id8">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id9">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id10">3.4.22 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id12">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id13">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id14">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id15">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id16">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id17">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id18">3.4.21 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id20">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id21">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#aggregation">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id22">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id23">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id24">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id25">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id26">3.4.20 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id28">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id29">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id30">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id31">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id32">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#tools">Tools</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id33">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id34">3.4.19 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id36">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id37">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id38">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id39">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id40">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id41">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id42">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id43">Tools</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id44">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id45">3.4.18 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id47">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id48">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id49">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id50">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id51">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id52">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id53">Tools</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id54">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id55">3.4.17 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id57">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id58">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id59">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id60">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#javascript">JavaScript</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id61">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id62">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id63">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id64">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id65">3.4.16 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id67">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id68">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id69">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id70">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id71">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id72">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id73">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id74">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id75">3.4.15 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id77">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id78">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id79">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id80">Storage</a><ul>
<li class="toctree-l4"><a class="reference internal" href="3.4-changelog.html#wiredtiger">WiredTiger</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id81">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id82">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id83">Tools</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id84">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id85">3.4.14 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id87">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id88">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id89">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id90">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id91">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id92">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id93">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id94">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id95">3.4.13 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id97">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id98">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id99">3.4.12 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id101">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id102">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id103">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id104">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id105">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id106">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id107">3.4.11 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id109">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id110">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id111">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id112">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#write-operations">Write Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id113">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id114">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id115">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id116">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id117">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id118">3.4.10 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id120">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id121">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id122">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id123">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id124">JavaScript</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id125">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id126">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id127">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id128">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id129">3.4.9 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id131">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id132">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id133">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id134">Write Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id135">JavaScript</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id136">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id137">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id138">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id139">3.4.7 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id141">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id142">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id143">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id144">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id145">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id146">Tools</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id147">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id148">3.4.6 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id150">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id151">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id152">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id153">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id154">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id155">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id156">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id157">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id158">3.4.5 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id160">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id161">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id162">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id163">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id164">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id165">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id166">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id167">3.4.4 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id169">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id170">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id171">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id172">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id173">Write Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id174">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id175">JavaScript</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id176">Storage</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id177">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id178">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id179">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id180">3.4.3 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id182">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id183">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id184">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id185">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id186">Storage</a><ul>
<li class="toctree-l4"><a class="reference internal" href="3.4-changelog.html#id187">WiredTiger</a></li>
<li class="toctree-l4"><a class="reference internal" href="3.4-changelog.html#mmap">MMAP</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#ttl">TTL</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id188">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id189">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id190">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id191">3.4.2 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id193">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id194">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id195">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id196">Write Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id197">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id198">Storage</a><ul>
<li class="toctree-l4"><a class="reference internal" href="3.4-changelog.html#id199">WiredTiger</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id200">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id201">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id202">Tools</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id203">Internals</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-changelog.html#id204">3.4.1 Changelog</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id206">Security</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id207">Sharding</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id208">Replication</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id209">Query</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id210">Aggregation</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id211">Storage</a><ul>
<li class="toctree-l4"><a class="reference internal" href="3.4-changelog.html#id212">WiredTiger</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id213">Operations</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id214">Build and Packaging</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id215">Tools</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-changelog.html#id216">Internals</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
<div class="section" id="jan-27-2020">
<span id="release-notes"></span><h3>3.4.24 - Jan 27, 2020<a class="headerlink" href="#jan-27-2020" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37772">SERVER-37772</a>: Platform Support: Add Community &amp; Enterprise RHEL 8 x64</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37135">SERVER-37135</a>: TLSVersionCounts needs to track and report TLS 1.3</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-36315">SERVER-36315</a>: After stepdown the CSRS dist lock manager keeps trying to unlock locks</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37846">SERVER-37846</a>: writeConcern can be satisfied with an arbiter if the write was committed</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-38945">SERVER-38945</a>: SSL performance regression</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-40355">SERVER-40355</a>: rs.config that contains an _id greater than the number of nodes will crash</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-43151">SERVER-43151</a>: Error in aggregation assertion at value.cpp:1368</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-44050">SERVER-44050</a>: Arrays along ‘hashed’ index key path are not correctly rejected</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/WT-4956">WT-4956</a>: Handle the case where 4 billion updates are made to a page without eviction</li>
<li><a class="reference internal" href="3.4-changelog.html#id1"><span class="std std-ref">3.4.24 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.24%27">All JIRA issues closed in 3.4.24</a></li>
</ul>
</div>
<div class="section" id="sep-16-2019">
<span id="id1"></span><h3>3.4.23 - Sep 16, 2019<a class="headerlink" href="#sep-16-2019" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-36394">SERVER-36394</a>: mongos should reset chunk size tracking
information when autosplit = false or splitvector returns too few
split points</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-41829">SERVER-41829</a>: findAndModify ignores filter expressions that
are not objects</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-42055">SERVER-42055</a>: Only acquire a collection IX lock to write the
lastVote document</li>
<li><a class="reference internal" href="3.4-changelog.html#id3"><span class="std std-ref">3.4.23 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.23%27">All JIRA issues closed in 3.4.23</a></li>
</ul>
</div>
<div class="section" id="aug-6-2019">
<span id="id2"></span><h3>3.4.22 - Aug 6, 2019<a class="headerlink" href="#aug-6-2019" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-17010">SERVER-17010</a>: Reduce file handle usage in File based Sorter.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-38984">SERVER-38984</a>: Attach IDs to users (CVE-2019-2386).</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-42089">SERVER-42089</a>: Platform Support: Remove Enterprise RHEL 6.7
zSeries</li>
<li><a class="reference internal" href="3.4-changelog.html#id10"><span class="std std-ref">3.4.22 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.22%27">All JIRA issues closed in 3.4.22</a></li>
</ul>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>Fixed issues include those that resolve the following Common
Vulnerabilities and Exposures (CVEs):</p>
<ul class="last simple">
<li>CVE-2019-2386 (See <a class="reference external" href="https://jira.mongodb.org/browse/SERVER-38984">SERVER-38984</a>)</li>
<li>CVE-2019-2389 (See <a class="reference external" href="https://jira.mongodb.org/browse/SERVER-40563">SERVER-40563</a>)</li>
<li>CVE-2019-2390 (See <a class="reference external" href="https://jira.mongodb.org/browse/SERVER-42233">SERVER-42233</a>)</li>
</ul>
</div>
</div>
<div class="section" id="jun-14-2019">
<span id="id3"></span><h3>3.4.21 - Jun 14, 2019<a class="headerlink" href="#jun-14-2019" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-39820">SERVER-39820</a>: Add the client IP address to the successful authentication log message</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-41213">SERVER-41213</a>: Unique background index builds may produce inconsistent keys</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37765">SERVER-37765</a>: Platform Support: Remove Ubuntu 14.04</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37774">SERVER-37774</a>: Platform Support: Remove Enterprise Ubuntu 16.04 PPCLE</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/WT-4615">WT-4615</a>: Sync backup file before returning backup cursor</li>
<li><a class="reference internal" href="3.4-changelog.html#id18"><span class="std std-ref">3.4.21 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.21%27">All JIRA issues closed in 3.4.21</a></li>
</ul>
</div>
<div class="section" id="mar-13-2019">
<span id="id4"></span><h3>3.4.20 - Mar 13, 2019<a class="headerlink" href="#mar-13-2019" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-39166">SERVER-39166</a>: $graphLookup should force a pipeline to split in sharded cluster</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-39723">SERVER-39723</a>: Change listIndexes command behavior to show in-progress index builds</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/TOOLS-2158">TOOLS-2158</a>: mongodump failing on Windows with “error opening system CA store: Access is denied.”</li>
<li><a class="reference internal" href="3.4-changelog.html#id26"><span class="std std-ref">3.4.20 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.20%27">All JIRA issues closed in 3.4.20</a></li>
</ul>
</div>
<div class="section" id="jan-28-2019">
<span id="id5"></span><h3>3.4.19 - Jan 28, 2019<a class="headerlink" href="#jan-28-2019" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-18985">SERVER-18985</a>: setParameter should log at level 0</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-22766">SERVER-22766</a>: Dynamic oplog sizing for WiredTiger nodes</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-33469">SERVER-33469</a>: Make syslog log lines consistent with mongod log lines</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37132">SERVER-37132</a>: Negation of $in with regex can incorrectly plan from the cache, leading to missing query results</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37182">SERVER-37182</a>: Different values when referencing whole object vs. a field of that object after $arrayToObject</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37616">SERVER-37616</a>: Implement tuneable batch size for the rangedeleter</li>
<li><a class="reference internal" href="3.4-changelog.html#id34"><span class="std std-ref">3.4.19 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.19%27">All JIRA issues closed in 3.4.19</a></li>
</ul>
</div>
<div class="section" id="nov-7-2018">
<span id="id6"></span><h3>3.4.18 - Nov 7, 2018<a class="headerlink" href="#nov-7-2018" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-25175">SERVER-25175</a>: listIndexes shouldn’t include in-progress background indexes</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-35418">SERVER-35418</a>: Allow specifying CAs for incoming and outgoing connections separately.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-36944">SERVER-36944</a>: applyOps does not permit unknown field names when creating a v:1 index.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-37058">SERVER-37058</a>: Update with numeric field names inside an array can cause validation to fail.</li>
<li><a class="reference internal" href="3.4-changelog.html#id45"><span class="std std-ref">3.4.18 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.18%27">All JIRA issues closed in 3.4.18</a></li>
</ul>
</div>
<div class="section" id="sep-7-2018">
<span id="id7"></span><h3>3.4.17 - Sep 7, 2018<a class="headerlink" href="#sep-7-2018" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-33857">SERVER-33857</a> Missing log redaction due to confusion with
Command::redactForLogging().</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-34846">SERVER-34846</a> Covered index with collated field returns
incorrect result when collation not involved in match or sort.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-36010">SERVER-36010</a> Change log messages for Windows stacktraces to
use error() or severe() rather than log().</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-34558">SERVER-34558</a>: Add SSL_version to client metadata logging.</li>
<li><a class="reference internal" href="3.4-changelog.html#id55"><span class="std std-ref">3.4.17 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.17%27">All JIRA issues closed in 3.4.17</a></li>
</ul>
</div>
<div class="section" id="jul-10-2018">
<span id="id8"></span><h3>3.4.16 - Jul 10, 2018<a class="headerlink" href="#jul-10-2018" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-32999">SERVER-32999</a>: Platform Support: Remove Debian 7 builds.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-29301">SERVER-29301</a>: Upgrade MozJS to ESR 45.9.0</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-5461">SERVER-5461</a>: Add <code class="docutils literal"><span class="pre">syncSourceHost</span></code> field to
<code class="docutils literal"><span class="pre">replSetGetStatus</span></code> output.</li>
<li><a class="reference internal" href="3.4-changelog.html#id65"><span class="std std-ref">3.4.16 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.16%27">All JIRA issues closed in 3.4.16</a></li>
</ul>
</div>
<div class="section" id="may-16-2018">
<span id="id9"></span><h3>3.4.15 - May 16, 2018<a class="headerlink" href="#may-16-2018" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-31535">SERVER-31535</a>: Platform Support: remove Ubuntu 12.04 builds.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-32923">SERVER-32923</a>: Platform Support: remove SLES11 builds.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-20056">SERVER-20056</a>: Log a startup warning if wiredTigerCacheSizeGB is &gt; 80% of RAM.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-28981">SERVER-28981</a>: Sharding balancer prefers shards in a specific order when moving chunks.</li>
<li><a class="reference internal" href="3.4-changelog.html#id75"><span class="std std-ref">3.4.15 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.15%27">All JIRA issues closed in 3.4.15</a></li>
</ul>
</div>
<div class="section" id="march-20-2018">
<span id="id10"></span><h3>3.4.14 - March 20, 2018<a class="headerlink" href="#march-20-2018" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-28151">SERVER-28151</a>: Authentication database should be synced first
during an initial sync.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-32886">SERVER-32886</a>:  Unnecessary sleeps during chunk migration.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-32933">SERVER-32933</a>: Allow <code class="docutils literal"><span class="pre">mongod</span></code> to start when unable to reach
LDAP server.</li>
<li><a class="reference internal" href="3.4-changelog.html#id85"><span class="std std-ref">3.4.14 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.14%27">All JIRA issues closed in 3.4.14</a></li>
</ul>
</div>
<div class="section" id="feb-10-2018">
<span id="id11"></span><h3>3.4.13 - Feb 10, 2018<a class="headerlink" href="#feb-10-2018" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-33238">SERVER-33238</a>: Prevent WiredTiger read ticket count from going negative.</li>
<li><a class="reference internal" href="3.4-changelog.html#id95"><span class="std std-ref">3.4.13 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.13%27">All JIRA issues closed in 3.4.13</a></li>
</ul>
</div>
<div class="section" id="feb-8-2018">
<span id="id12"></span><h3>3.4.12 - Feb 8, 2018<a class="headerlink" href="#feb-8-2018" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-31437">SERVER-31437</a>: Fix parsing of <code class="docutils literal"><span class="pre">mongo</span> <span class="pre">host/db</span></code> connect string.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-32875">SERVER-32875</a>: Don’t stall ftdc due to running out of tickets.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-33089">SERVER-33089</a>: Unable to start queryable mongod because it
failed to regenerate index for <code class="docutils literal"><span class="pre">admin.system.users</span></code>.</li>
<li><a class="reference internal" href="3.4-changelog.html#id99"><span class="std std-ref">3.4.12 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.12%27">All JIRA issues closed in 3.4.12</a></li>
</ul>
</div>
<div class="section" id="jan-31-2018">
<span id="id13"></span><h3>3.4.11 - Jan 31, 2018<a class="headerlink" href="#jan-31-2018" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-19605">SERVER-19605</a>: Oplog timeout should be configurable.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-19919">SERVER-19919</a>: Chunks that exceed 250000 docs but are under half chunk size get marked as jumbo.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-29293">SERVER-29293</a>: Recipient shard fails to abort migration on stepdown.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-32001">SERVER-32001</a>: unindexing a key in a partial unique index may cause server crash</li>
<li><a class="reference internal" href="3.4-changelog.html#id107"><span class="std std-ref">3.4.11 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.11%27">All JIRA issues closed in 3.4.11</a></li>
</ul>
</div>
<div class="section" id="oct-31-2017">
<span id="id14"></span><h3>3.4.10 - Oct 31, 2017<a class="headerlink" href="#oct-31-2017" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-15723">SERVER-15723</a>: Avoid G_X lock for rename_collection within
database</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-31049">SERVER-31049</a>: View with collation doesn’t work as expected
in sharded cluster</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-29287">SERVER-29287</a>: Upgrade pcre to 8.41</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-31204">SERVER-31204</a>: Calling <cite>shardCollection</cite> after
<cite>enableSharding</cite> may fail if executed against different mongos</li>
<li><a class="reference internal" href="3.4-changelog.html#id118"><span class="std std-ref">3.4.10 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.10%27">All JIRA issues closed in 3.4.10</a></li>
</ul>
</div>
<div class="section" id="sept-11-2017">
<span id="id15"></span><h3>3.4.9 - Sept 11, 2017<a class="headerlink" href="#sept-11-2017" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-20392">SERVER-20392</a>: Sharding an existing small collection results in large number of chunks</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-30189">SERVER-30189</a>: Reduce calls to allocator for large $in expressions</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-30487">SERVER-30487</a>: RangeDeleter holds WT transaction open while waiting for majority</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-30636">SERVER-30636</a>: Range deleter assert failed because of replication lag</li>
<li><a class="reference internal" href="3.4-changelog.html#id129"><span class="std std-ref">3.4.9 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.9%27">All JIRA issues closed in 3.4.9</a></li>
</ul>
</div>
<div class="section" id="aug-8-2017">
<span id="id16"></span><h3>3.4.7 – Aug 8, 2017<a class="headerlink" href="#aug-8-2017" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-29282">SERVER-29282</a>: BSON Document Size can be exceeded when grouping inserts on SECONDARY nodes</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-29568">SERVER-29568</a>: Enable configuration of OpenSSL cipher suite via <a class="reference internal" href="../reference/parameters.html#param.opensslCipherConfig" title="opensslCipherConfig"><code class="xref mongodb mongodb-parameter docutils literal"><span class="pre">setParameter</span></code></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-29817">SERVER-29817</a>:  Optimize incremental update performance of ChunkManager and CollectionMetadata</li>
<li><a class="reference internal" href="3.4-changelog.html#id139"><span class="std std-ref">3.4.7 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.7%27">All JIRA issues closed in 3.4.7</a></li>
</ul>
</div>
<div class="section" id="jul-5-2017">
<span id="id17"></span><h3>3.4.6 – Jul 5, 2017<a class="headerlink" href="#jul-5-2017" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27347">SERVER-27347</a>: Only close idle cached cursors on the
WiredTiger ident that is busy.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-29618">SERVER-29618</a>: <code class="docutils literal"><span class="pre">$geoWithin</span></code> in aggregation pipeline after
<code class="docutils literal"><span class="pre">$lookup</span></code> and <code class="docutils literal"><span class="pre">$unwind</span></code> returns incorrect results.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/WT-3362">WT-3362</a>: Cursor opens should never block for the duration of a checkpoint.</li>
<li><a class="reference internal" href="3.4-changelog.html#id148"><span class="std std-ref">3.4.6 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.6%27">All JIRA issues closed in 3.4.6</a></li>
</ul>
</div>
<div class="section" id="jun-14-2017">
<span id="id18"></span><h3>3.4.5 – Jun 14, 2017<a class="headerlink" href="#jun-14-2017" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-28952">SERVER-28952</a>: Multikey indexes should not be eligible for
DISTINCT_SCAN if distinct key is an array component.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-28427">SERVER-28427</a>: GlobalLock with timeout can still block indefinitely.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-29018">SERVER-29018</a> <a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a> can segfault in <code class="docutils literal"><span class="pre">getMore</span></code>
on views with find batchSize of 0.</li>
<li><a class="reference internal" href="3.4-changelog.html#id158"><span class="std std-ref">3.4.5 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.5%27">All JIRA issues closed in 3.4.5</a></li>
</ul>
</div>
<div class="section" id="apr-21-2017">
<span id="id19"></span><h3>3.4.4 – Apr 21, 2017<a class="headerlink" href="#apr-21-2017" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-18794">SERVER-18794</a>: Add an aggregation operator
<a class="reference internal" href="../reference/operator/aggregation/objectToArray.html#exp._S_objectToArray" title="$objectToArray"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$objectToArray</span></code></a> to convert an object to an array of key,
value pairs.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-23310">SERVER-23310</a>: Add an aggregation operator
<a class="reference internal" href="../reference/operator/aggregation/arrayToObject.html#exp._S_arrayToObject" title="$arrayToObject"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$arrayToObject</span></code></a> to convert an array of pairs to an
object.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-22611">SERVER-22611</a>: ChunkManager refresh can occasionally cause a
full reload.</li>
<li><a class="reference internal" href="3.4-changelog.html#id167"><span class="std std-ref">3.4.4 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.4%27">All JIRA issues closed in 3.4.4</a></li>
</ul>
</div>
<div class="section" id="mar-28-2017">
<span id="id20"></span><h3>3.4.3 – Mar 28, 2017<a class="headerlink" href="#mar-28-2017" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27863">SERVER-27863</a>: Reschedule firing of early alarms in
NetworkInterfaceASIO to avoid <a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a> crash.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-28017">SERVER-28017</a>: <a class="reference internal" href="../reference/operator/query/ne.html#op._S_ne" title="$ne"><code class="xref mongodb mongodb-query docutils literal"><span class="pre">$ne</span></code></a> should respect collection’s
default collation.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27700">SERVER-27700</a>: Improve WiredTiger performance on secondary
when cache is full.</li>
<li><a class="reference internal" href="3.4-changelog.html#id180"><span class="std std-ref">3.4.3 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.3%27">All JIRA issues closed in 3.4.3</a></li>
</ul>
</div>
<div class="section" id="feb-1-2017">
<span id="id21"></span><h3>3.4.2 – Feb 1, 2017<a class="headerlink" href="#feb-1-2017" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27125">SERVER-27125</a>: Arbiters in pv1 should vote no in elections if
they can see a healthy primary of equal or greater priority to the
candidate.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27584">SERVER-27584</a> Add support for filter to listDatabases</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/WT-2670">WT-2670</a> Inefficient I/O when read full DB (poor readahead)</li>
<li><a class="reference internal" href="3.4-changelog.html#id191"><span class="std std-ref">3.4.2 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.2%27">All JIRA issues closed in 3.4.2</a></li>
</ul>
</div>
<div class="section" id="dec-20-2016">
<span id="id22"></span><h3>3.4.1 – Dec 20, 2016<a class="headerlink" href="#dec-20-2016" title="Permalink to this headline">¶</a></h3>
<p>Issues fixed:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27124">SERVER-27124</a>: Disallow <code class="docutils literal"><span class="pre">readConcern:</span> <span class="pre">majority</span></code> reads on
replica set protocolVersion 0 (pv0).</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27201">SERVER-27201</a>: $graphLookup triggers null pointer dereference.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27207">SERVER-27207</a>: Find operation with a sort on a view via
<code class="docutils literal"><span class="pre">mongos</span></code> may incorrectly return empty result set.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27213">SERVER-27213</a>: Two <code class="docutils literal"><span class="pre">$match</span></code> pipeline stages can combine
incorrectly to produce incorrect results.</li>
<li><a class="reference internal" href="3.4-changelog.html#id204"><span class="std std-ref">3.4.1 Changelog</span></a></li>
<li><a class="reference external" href="https://jira.mongodb.org/issues/?jql=project%20in%20(SERVER%2CTOOLS%2CWT)%20AND%20resolution%3D%27Fixed%27%20and%20fixversion%3D%273.4.1%27">All JIRA issues closed in 3.4.1</a></li>
</ul>
</div>
</div>
<div class="section" id="sharded-cluster">
<span id="rel-notes-sharded-cluster"></span><h2>Sharded Cluster<a class="headerlink" href="#sharded-cluster" title="Permalink to this headline">¶</a></h2>
<div class="section" id="membership-awareness">
<h3>Membership Awareness<a class="headerlink" href="#membership-awareness" title="Permalink to this headline">¶</a></h3>
<p>Starting in 3.4, sharded cluster components (shards, config servers,
<a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a> instances) recognize their membership in a sharded
cluster, including the name of the sharded cluster, the location of the
config servers.</p>
<p>To support this awareness:</p>
<ul>
<li><dl class="first docutils">
<dt><code class="docutils literal"><span class="pre">shardsvr</span></code> Requirement</dt>
<dd><p class="first">For a 3.4 sharded cluster, <a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a> instances for the
shards <strong>must</strong> explicitly specify its role as a <code class="docutils literal"><span class="pre">shardsvr</span></code>,
either via the configuration file setting
<a class="reference internal" href="../reference/configuration-options.html#sharding.clusterRole" title="sharding.clusterRole"><code class="xref mongodb mongodb-setting docutils literal"><span class="pre">sharding.clusterRole</span></code></a> or via the command line option
<a class="reference internal" href="../reference/program/mongod.html#cmdoption-mongod-shardsvr"><code class="xref std std-option docutils literal"><span class="pre">--shardsvr</span></code></a>.</p>
<div class="last admonition note">
<p class="first admonition-title">Note</p>
<p class="last">Default port for <a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a> instances with the <code class="docutils literal"><span class="pre">shardsvr</span></code>
role is <code class="docutils literal"><span class="pre">27018</span></code>. To use a different port, specify
<a class="reference internal" href="../reference/configuration-options.html#net.port" title="net.port"><code class="xref mongodb mongodb-setting docutils literal"><span class="pre">net.port</span></code></a> setting or <code class="docutils literal"><span class="pre">--port</span></code> option.</p>
</div>
</dd>
</dl>
</li>
<li><dl class="first docutils">
<dt>3.4 <code class="docutils literal"><span class="pre">mongos</span></code> Incompatibility with Earlier Versions of <code class="docutils literal"><span class="pre">mongod</span></code></dt>
<dd><p class="first last">Version 3.4 <a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a> instances cannot connect to
earlier versions of <a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a> instances.</p>
</dd>
</dl>
</li>
</ul>
</div>
<div class="section" id="balancer-on-config-server-primary">
<h3>Balancer on Config Server Primary<a class="headerlink" href="#balancer-on-config-server-primary" title="Permalink to this headline">¶</a></h3>
<p>The balancer process has moved from the <a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a> to the
primary member of the config server replica set. Associated with this
change:</p>
<ul class="simple">
<li>The primary of the CSRS config server holds the <code class="docutils literal"><span class="pre">&quot;balancer&quot;</span></code> lock,
using a process id named <code class="docutils literal"><span class="pre">&quot;ConfigServer&quot;</span></code>, which is never released.</li>
<li>MongoDB 3.4 adds:<ul>
<li><a class="reference internal" href="../reference/command/balancerStart.html#dbcmd.balancerStart" title="balancerStart"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">balancerStart</span></code></a> command and updates the 3.4
<a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell method <a class="reference internal" href="../reference/method/sh.startBalancer.html#sh.startBalancer" title="sh.startBalancer()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.startBalancer()</span></code></a> to wrap
the new command. A 3.2 or earlier <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell method
<a class="reference internal" href="../reference/method/sh.startBalancer.html#sh.startBalancer" title="sh.startBalancer()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.startBalancer()</span></code></a> is incompatible with a 3.4 sharded
cluster.</li>
<li><a class="reference internal" href="../reference/command/balancerStop.html#dbcmd.balancerStop" title="balancerStop"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">balancerStop</span></code></a> command and updates the 3.4
<a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell method <a class="reference internal" href="../reference/method/sh.stopBalancer.html#sh.stopBalancer" title="sh.stopBalancer()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.stopBalancer()</span></code></a> to wrap
the new command. A 3.2 or earlier <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell method
<a class="reference internal" href="../reference/method/sh.stopBalancer.html#sh.stopBalancer" title="sh.stopBalancer()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.stopBalancer()</span></code></a> is incompatible with a 3.4 sharded
cluster.</li>
<li><a class="reference internal" href="../reference/command/balancerStatus.html#dbcmd.balancerStatus" title="balancerStatus"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">balancerStatus</span></code></a> command.</li>
</ul>
</li>
<li>MongoDB 3.4 deprecates <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell method
<a class="reference internal" href="../reference/method/sh.getBalancerHost.html#sh.getBalancerHost" title="sh.getBalancerHost()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.getBalancerHost()</span></code></a>. A 3.2 or earlier <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a>
shell method <a class="reference internal" href="../reference/method/sh.getBalancerHost.html#sh.getBalancerHost" title="sh.getBalancerHost()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.getBalancerHost()</span></code></a> is incompatible with a
3.4 sharded cluster.</li>
<li>MongoDB 3.4 removes the following configuration options from the
<a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a>:<ul>
<li><code class="xref mongodb mongodb-setting docutils literal"><span class="pre">sharding.chunkSize</span></code> configuration file setting and
<code class="docutils literal"><span class="pre">--chunkSize</span></code> command-line option</li>
<li><code class="xref mongodb mongodb-setting docutils literal"><span class="pre">sharding.autoSplit</span></code> configuration file setting and
<code class="docutils literal"><span class="pre">--noAutoSplit</span></code> command-line option</li>
</ul>
</li>
</ul>
</div>
<div class="section" id="faster-balancing">
<h3>Faster Balancing<a class="headerlink" href="#faster-balancing" title="Permalink to this headline">¶</a></h3>
<p>Starting in MongoDB 3.4:</p>
<ul class="simple">
<li>For <a class="reference internal" href="../core/wiredtiger.html#storage-wiredtiger"><span class="std std-ref">WiredTiger</span></a>, the default value
<code class="docutils literal"><span class="pre">secondaryThrottle</span></code> is <code class="docutils literal"><span class="pre">false</span></code> for all chunk migrations. The
balancer does not wait for replication to a secondary and instead
continues with the next document.</li>
<li>MongoDB can perform parallel chunk migrations. Similar to earlier
versions, a shard can participate in at most one migration at a time.
Observing this restriction, for a sharded cluster with <em>n</em> shards,
MongoDB can perform at most <em>n/2</em> (rounded down) simultaneous chunk
migrations.</li>
</ul>
</div>
<div class="section" id="removal-of-support-for-sccc-config-servers">
<span id="remove-sccc"></span><h3>Removal of Support for SCCC Config Servers<a class="headerlink" href="#removal-of-support-for-sccc-config-servers" title="Permalink to this headline">¶</a></h3>
<p>3.4 sharded clusters no longer support the use of mirrored (SCCC)
<a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a> instances as config servers. The use of SCCC config
servers, deprecated in the 3.2 release, is no longer valid. Instead,
deploy your config servers as a replica set (CSRS).</p>
<p>To upgrade your sharded cluster to version 3.4, the config servers must
be running as a replica set.</p>
<p>To convert your existing config servers from SCCC to CSRS, see the
<a class="reference external" href="https://docs.mongodb.com/v3.4/tutorial/upgrade-config-servers-to-replica-set">Upgrade Config Servers to Replica Set</a>.</p>
</div>
<div class="section" id="sharding-zones">
<h3>Sharding Zones<a class="headerlink" href="#sharding-zones" title="Permalink to this headline">¶</a></h3>
<p>MongoDB 3.4 introduces <a class="reference internal" href="../core/zone-sharding.html"><span class="doc">Zones</span></a>, which supersedes
tag-aware sharding available in earlier versions.</p>
<p>To support zones, MongoDB introduces the following commands and
<a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell helpers:</p>
<table border="1" class="docutils">
<colgroup>
<col width="50%" />
<col width="50%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Commands</th>
<th class="head"><cite>mongo</cite> Shell Methods</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/command/addShardToZone.html#dbcmd.addShardToZone" title="addShardToZone"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">addShardToZone</span></code></a></td>
<td><a class="reference internal" href="../reference/method/sh.addShardToZone.html#sh.addShardToZone" title="sh.addShardToZone()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.addShardToZone()</span></code></a></td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/command/removeShardFromZone.html#dbcmd.removeShardFromZone" title="removeShardFromZone"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">removeShardFromZone</span></code></a></td>
<td><a class="reference internal" href="../reference/method/sh.removeShardFromZone.html#sh.removeShardFromZone" title="sh.removeShardFromZone()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.removeShardFromZone()</span></code></a></td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/command/updateZoneKeyRange.html#dbcmd.updateZoneKeyRange" title="updateZoneKeyRange"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">updateZoneKeyRange</span></code></a></td>
<td><div class="first last line-block">
<div class="line"><a class="reference internal" href="../reference/method/sh.updateZoneKeyRange.html#sh.updateZoneKeyRange" title="sh.updateZoneKeyRange()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.updateZoneKeyRange()</span></code></a></div>
<div class="line"><a class="reference internal" href="../reference/method/sh.removeRangeFromZone.html#sh.removeRangeFromZone" title="sh.removeRangeFromZone()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.removeRangeFromZone()</span></code></a></div>
</div>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="section" id="replica-set">
<span id="id23"></span><h2>Replica Set<a class="headerlink" href="#replica-set" title="Permalink to this headline">¶</a></h2>
<div class="section" id="default-journaling-behavior-of-majority-write-concern">
<h3>Default Journaling Behavior of <code class="docutils literal"><span class="pre">majority</span></code> Write Concern<a class="headerlink" href="#default-journaling-behavior-of-majority-write-concern" title="Permalink to this headline">¶</a></h3>
<p>A new replica set configuration setting
<a class="reference internal" href="../reference/replica-configuration.html#rsconf.writeConcernMajorityJournalDefault" title="writeConcernMajorityJournalDefault"><code class="xref mongodb mongodb-rsconf docutils literal"><span class="pre">writeConcernMajorityJournalDefault</span></code></a> determines whether an
acknowledgement for a write concern of <a class="reference internal" href="../reference/write-concern.html#writeconcern.&quot;majority&quot;" title="&quot;majority&quot;"><code class="xref mongodb mongodb-writeconcern docutils literal"><span class="pre">majority</span></code></a> returns after the majority of the voting members apply
the write in memory or to the on-disk journal <em>if</em> the <a class="reference internal" href="../reference/write-concern.html#wc-j"><span class="std std-ref">j</span></a>
option is unspecified in the write concern.</p>
</div>
<div class="section" id="adjustable-catchup-period-for-newly-elected-primary">
<h3>Adjustable Catchup Period for Newly Elected Primary<a class="headerlink" href="#adjustable-catchup-period-for-newly-elected-primary" title="Permalink to this headline">¶</a></h3>
<p>A new replica set configuration setting
<a class="reference internal" href="../reference/replica-configuration.html#rsconf.settings.catchUpTimeoutMillis" title="settings.catchUpTimeoutMillis"><code class="xref mongodb mongodb-rsconf docutils literal"><span class="pre">settings.catchUpTimeoutMillis</span></code></a> defines the time limit for a
newly elected primary to catch up with the other replica set members
that may have more recent writes.</p>
</div>
<div class="section" id="linearizable-read-concern">
<h3>Linearizable Read Concern<a class="headerlink" href="#linearizable-read-concern" title="Permalink to this headline">¶</a></h3>
<p>MongoDB 3.4 introduces a read concern level of
<a class="reference internal" href="../reference/read-concern-linearizable.html#readconcern.&quot;linearizable&quot;" title="&quot;linearizable&quot;"><code class="xref mongodb mongodb-readconcern docutils literal"><span class="pre">&quot;linearizable&quot;</span></code></a> to read data that reflects all successful
writes issued with a <a class="reference internal" href="../reference/write-concern.html#writeconcern.&quot;majority&quot;" title="&quot;majority&quot;"><code class="xref mongodb mongodb-writeconcern docutils literal"><span class="pre">&quot;majority&quot;</span></code></a> <em>and</em> acknowledged
prior to the start of the read operation. Linearizable read concern
guarantees only apply if read operations specify a query filter that
uniquely identifies a single document.</p>
<p>Linearizable read concern is available for all MongoDB supported
<a class="reference internal" href="../core/storage-engines.html"><span class="doc">storage engines</span></a>.</p>
<p>Combined with <a class="reference internal" href="../reference/write-concern.html#writeconcern.&quot;majority&quot;" title="&quot;majority&quot;"><code class="xref mongodb mongodb-writeconcern docutils literal"><span class="pre">&quot;majority&quot;</span></code></a> write concern,
<a class="reference internal" href="../reference/read-concern-linearizable.html#readconcern.&quot;linearizable&quot;" title="&quot;linearizable&quot;"><code class="xref mongodb mongodb-readconcern docutils literal"><span class="pre">&quot;linearizable&quot;</span></code></a> read concern enables multiple threads to
perform reads and writes on a single document as if a single thread
performed these operations in real time; that is, the corresponding
schedule for these reads and writes is considered linearizable.</p>
<p>Reads with linearizable read concern may be significantly slower than
reads with <a class="reference internal" href="../reference/read-concern-majority.html#readconcern.&quot;majority&quot;" title="&quot;majority&quot;"><code class="xref mongodb mongodb-readconcern docutils literal"><span class="pre">&quot;majority&quot;</span></code></a> or <a class="reference internal" href="../reference/read-concern-local.html#readconcern.&quot;local&quot;" title="&quot;local&quot;"><code class="xref mongodb mongodb-readconcern docutils literal"><span class="pre">&quot;local&quot;</span></code></a> read
concerns. Always use <code class="docutils literal"><span class="pre">maxTimeMS</span></code> with linearizable read concern, in
case a majority of data bearing members are unavailable. For example:</p>
<div class="button-code-block">
<div class="button-row">
<a class="code-button--copy code-button" role="button">
copy</a>
</div>
<div class="copyable-code-block highlight-javascript"><div class="highlight"><pre><span></span><span class="nx">db</span><span class="p">.</span><span class="nx">restaurants</span><span class="p">.</span><span class="nx">find</span><span class="p">(</span> <span class="p">{</span> <span class="nx">_id</span><span class="o">:</span> <span class="mi">5</span> <span class="p">}</span> <span class="p">).</span><span class="nx">readConcern</span><span class="p">(</span><span class="s2">&quot;linearizable&quot;</span><span class="p">).</span><span class="nx">maxTimeMS</span><span class="p">(</span><span class="mi">10000</span><span class="p">)</span>

<span class="nx">db</span><span class="p">.</span><span class="nx">runCommand</span><span class="p">(</span> <span class="p">{</span>
     <span class="nx">find</span><span class="o">:</span> <span class="s2">&quot;restaurants&quot;</span><span class="p">,</span>
     <span class="nx">filter</span><span class="o">:</span> <span class="p">{</span> <span class="nx">_id</span><span class="o">:</span> <span class="mi">5</span> <span class="p">},</span>
     <span class="nx">readConcern</span><span class="o">:</span> <span class="p">{</span> <span class="nx">level</span><span class="o">:</span> <span class="s2">&quot;linearizable&quot;</span> <span class="p">},</span>
     <span class="nx">maxTimeMS</span><span class="o">:</span> <span class="mi">10000</span>
<span class="p">}</span> <span class="p">)</span>
</pre></div>
</div>
</div>
<p>For more information on read concern, including operations that support
read concerns, see <a class="reference internal" href="../reference/read-concern.html"><span class="doc">Read Concern</span></a>.</p>
</div>
<div class="section" id="improved-initial-sync">
<h3>Improved Initial Sync<a class="headerlink" href="#improved-initial-sync" title="Permalink to this headline">¶</a></h3>
<ul>
<li><p class="first">MongoDB 3.4 improves the performance of <a class="reference internal" href="../core/replica-set-sync.html#replica-set-initial-sync"><span class="std std-ref">initial sync</span></a> by having initial sync build the indexes
as the documents are copied.</p>
</li>
<li><p class="first">MongoDB 3.4 improves the <a class="reference internal" href="../core/replica-set-sync.html#init-sync-retry"><span class="std std-ref">initial sync retry logic</span></a> to be more resilient to intermittent failures on
the network.</p>
</li>
<li><p class="first">To avoid potential data corruption, MongoDB 3.4 fails and restarts
<a class="reference internal" href="../core/replica-set-sync.html#replica-set-initial-sync"><span class="std std-ref">initial sync</span></a> if a collection is
renamed on the sync source during the initial sync. With MongoDB 3.2.11
or earlier, initial syncs did not fail and restart but instead
continued the process, which could lead to potential data corruption.</p>
<p>For details, see <a class="reference internal" href="3.4-compatibility.html#compatibility-initial-sync"><span class="std std-ref">Initial Sync and renameCollection</span></a>.</p>
</li>
<li><p class="first">Modified <a class="reference internal" href="../reference/command/replSetGetStatus.html#dbcmd.replSetGetStatus" title="replSetGetStatus"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">replSetGetStatus</span></code></a> command to accept the optional
<code class="docutils literal"><span class="pre">initialSync:</span> <span class="pre">1</span></code> in the command to report on initial sync status
and progress if run on the secondary:</p>
<div class="button-code-block">
<div class="button-row">
<a class="code-button--copy code-button" role="button">
copy</a>
</div>
<div class="copyable-code-block highlight-javascript"><div class="highlight"><pre><span></span><span class="nx">db</span><span class="p">.</span><span class="nx">adminCommand</span><span class="p">(</span> <span class="p">{</span> <span class="nx">replSetGetStatus</span><span class="o">:</span> <span class="mi">1</span><span class="p">,</span> <span class="nx">initialSync</span><span class="o">:</span> <span class="mi">1</span> <span class="p">}</span> <span class="p">)</span>
</pre></div>
</div>
</div>
</li>
</ul>
</div>
</div>
<div class="section" id="decimal-type">
<span id="decimal"></span><h2>Decimal Type<a class="headerlink" href="#decimal-type" title="Permalink to this headline">¶</a></h2>
<p>3.4 adds support for the <a class="reference external" href="https://en.wikipedia.org/wiki/Decimal128_floating-point_format">decimal128 format</a> with
the new <code class="docutils literal"><span class="pre">decimal</span></code> data type. The decimal128 format supports numbers with
up to 34 decimal digits (i.e. significant digits) and an exponent range
of −6143 to +6144.</p>
<p>To support the format, the <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell adds the
<a class="reference internal" href="../core/shell-types.html#shell-type-decimal"><span class="std std-ref">NumberDecimal</span></a> wrapper.</p>
<div class="button-code-block">
<div class="button-row">
<a class="code-button--copy code-button" role="button">
copy</a>
</div>
<div class="copyable-code-block highlight-javascript"><div class="highlight"><pre><span></span><span class="nx">db</span><span class="p">.</span><span class="nx">inventory</span><span class="p">.</span><span class="nx">insert</span><span class="p">(</span> <span class="p">{</span><span class="nx">_id</span><span class="o">:</span> <span class="mi">1</span><span class="p">,</span> <span class="nx">item</span><span class="o">:</span> <span class="s2">&quot;The Scream&quot;</span><span class="p">,</span> <span class="nx">price</span><span class="o">:</span> <span class="nx">NumberDecimal</span><span class="p">(</span><span class="s2">&quot;9.99&quot;</span><span class="p">),</span> <span class="nx">quantity</span><span class="o">:</span> <span class="mi">4</span> <span class="p">}</span> <span class="p">)</span>
</pre></div>
</div>
</div>
<p>When performing <a class="reference internal" href="../reference/bson-type-comparison-order.html#bson-types-comparison-order"><span class="std std-ref">comparisons</span></a> among
different numerical types, MongoDB performs comparison on the exact
stored numerical values without first converting values to a common
type.</p>
<p>Unlike the <code class="docutils literal"><span class="pre">double</span></code> data type, which only stores an approximation of
the decimal values, the <code class="docutils literal"><span class="pre">decimal</span></code> data type stores the exact value.
For example, a <code class="docutils literal"><span class="pre">decimal</span></code> <code class="docutils literal"><span class="pre">NumberDecimal(&quot;9.99&quot;)</span></code> has a precise
value of <code class="docutils literal"><span class="pre">9.99</span></code> where as a double <code class="docutils literal"><span class="pre">9.99</span></code> would have an approximate
value of <code class="docutils literal"><span class="pre">9.9900000000000002131628...</span></code>.</p>
<p>To test for <code class="docutils literal"><span class="pre">decimal</span></code> type, use the <a class="reference internal" href="../reference/operator/query/type.html#op._S_type" title="$type"><code class="xref mongodb mongodb-query docutils literal"><span class="pre">$type</span></code></a> operator with the
literal <code class="docutils literal"><span class="pre">&quot;decimal&quot;</span></code> or <code class="docutils literal"><span class="pre">19</span></code>.</p>
<div class="button-code-block">
<div class="button-row">
<a class="code-button--copy code-button" role="button">
copy</a>
</div>
<div class="copyable-code-block highlight-javascript"><div class="highlight"><pre><span></span><span class="nx">db</span><span class="p">.</span><span class="nx">inventory</span><span class="p">.</span><span class="nx">find</span><span class="p">(</span> <span class="p">{</span> <span class="nx">price</span><span class="o">:</span> <span class="p">{</span> <span class="nx">$type</span><span class="o">:</span> <span class="s2">&quot;decimal&quot;</span> <span class="p">}</span> <span class="p">}</span> <span class="p">)</span>
</pre></div>
</div>
</div>
<p>To use the new <code class="docutils literal"><span class="pre">decimal</span></code> data type with a MongoDB driver, an upgrade
to a driver version that supports the feature is necessary.</p>
</div>
<div class="section" id="aggregation">
<span id="rel-notes-aggregation-cluster"></span><h2>Aggregation<a class="headerlink" href="#aggregation" title="Permalink to this headline">¶</a></h2>
<div class="section" id="new-aggregation-stage-for-recursive-search">
<h3>New Aggregation Stage for Recursive Search<a class="headerlink" href="#new-aggregation-stage-for-recursive-search" title="Permalink to this headline">¶</a></h3>
<p>3.4 introduces a stage to the <a class="reference internal" href="../core/aggregation-pipeline.html"><span class="doc">aggregation pipeline</span></a> that allows for recursive search.</p>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Stage</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/graphLookup.html#pipe._S_graphLookup" title="$graphLookup"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$graphLookup</span></code></a></td>
<td>Performs a recursive search on a collection. To each output
document, adds a new array field that contains the traversal
results of the recursive search for that document.</td>
</tr>
</tbody>
</table>
<div class="admonition seealso">
<p class="first admonition-title">See also</p>
<p class="last"><a class="reference external" href="https://www.mongodb.com/presentations/webinar-working-with-graph-data-in-mongodb?jmp=docs">Webinar: Working with Graph Data in MongoDB</a></p>
</div>
</div>
<div class="section" id="new-aggregation-stages-for-faceted-search">
<h3>New Aggregation Stages for Faceted Search<a class="headerlink" href="#new-aggregation-stages-for-faceted-search" title="Permalink to this headline">¶</a></h3>
<p>Faceted search allows for the categorization of documents into
classifications. For example, given a collection of inventory
documents, you may want to classify items by a single category, such as
by the price range, or by multiple categories, such as by price range
as well as separately by the departments.</p>
<p>3.4 introduces stages to the <a class="reference internal" href="../core/aggregation-pipeline.html"><span class="doc">aggregation pipeline</span></a> that allow for faceted search.</p>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Stage</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/bucket.html#pipe._S_bucket" title="$bucket"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$bucket</span></code></a></td>
<td>Categorizes or groups incoming documents into buckets that
represent a range of values for a specified expression.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/bucketAuto.html#pipe._S_bucketAuto" title="$bucketAuto"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$bucketAuto</span></code></a></td>
<td>Categorizes or groups incoming documents into specified number
of buckets that represent a range of values for a specified
expression. MongoDB automatically determines the bucket
boundaries.</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/facet.html#pipe._S_facet" title="$facet"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$facet</span></code></a></td>
<td>Processes multiple <a class="reference internal" href="../core/aggregation-pipeline.html#id1"><span class="std std-ref">pipelines</span></a> on
the input documents and outputs a document that contains the
results of these pipelines. By specifying facet-related stages
(<a class="reference internal" href="../reference/operator/aggregation/bucket.html#pipe._S_bucket" title="$bucket"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$bucket</span></code></a>, <a class="reference internal" href="../reference/operator/aggregation/bucketAuto.html#pipe._S_bucketAuto" title="$bucketAuto"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$bucketAuto</span></code></a>, and
<a class="reference internal" href="../reference/operator/aggregation/sortByCount.html#pipe._S_sortByCount" title="$sortByCount"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$sortByCount</span></code></a>) in these pipelines, <a class="reference internal" href="../reference/operator/aggregation/facet.html#pipe._S_facet" title="$facet"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$facet</span></code></a>
allows for multi-faceted search.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/sortByCount.html#pipe._S_sortByCount" title="$sortByCount"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$sortByCount</span></code></a></td>
<td>Categorizes or groups incoming documents by a specified
expression to compute the count for each group. Output documents
are sorted in descending order by the count.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="new-aggregation-stages-to-facilitate-reshaping-documents">
<h3>New Aggregation Stages to Facilitate Reshaping Documents<a class="headerlink" href="#new-aggregation-stages-to-facilitate-reshaping-documents" title="Permalink to this headline">¶</a></h3>
<p>3.4 introduces stages to the <a class="reference internal" href="../core/aggregation-pipeline.html"><span class="doc">aggregation pipeline</span></a> that faciliate replacing documents as
well as adding new fields.</p>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Stage</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/addFields.html#pipe._S_addFields" title="$addFields"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$addFields</span></code></a></td>
<td>Adds new fields to documents. The stage outputs documents that
contains all existing fields from the input documents as well as
the newly added fields.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/replaceRoot.html#pipe._S_replaceRoot" title="$replaceRoot"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$replaceRoot</span></code></a></td>
<td>Replaces a document with the specified document. You can specify
a document embedded in the input document to promote the
embedded document to the top level.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="new-aggregation-stage-to-count">
<h3>New Aggregation Stage to Count<a class="headerlink" href="#new-aggregation-stage-to-count" title="Permalink to this headline">¶</a></h3>
<p>3.4 introduces a new stage to the <a class="reference internal" href="../core/aggregation-pipeline.html"><span class="doc">aggregation pipeline</span></a> that faciliate counting document.</p>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Stage</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/count.html#pipe._S_count" title="$count"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$count</span></code></a></td>
<td>Returns a document that contains a count of the number of
documents input to the stage.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="new-aggregation-array-operators">
<h3>New Aggregation Array Operators<a class="headerlink" href="#new-aggregation-array-operators" title="Permalink to this headline">¶</a></h3>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Operator</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/in.html#exp._S_in" title="$in"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$in</span></code></a></td>
<td>Returns a boolean that indicates if a specified value is in an
array.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/indexOfArray.html#exp._S_indexOfArray" title="$indexOfArray"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$indexOfArray</span></code></a></td>
<td>Searches an array for an occurence of a specified value and
returns the array index (zero-based) of the first occurence.</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/range.html#exp._S_range" title="$range"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$range</span></code></a></td>
<td>Returns an array whose elements are a generated sequence of
numbers.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/reverseArray.html#exp._S_reverseArray" title="$reverseArray"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$reverseArray</span></code></a></td>
<td>Returns an output array whose elements are those of the input
array but in reverse order.</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/reduce.html#exp._S_reduce" title="$reduce"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$reduce</span></code></a></td>
<td>Takes an array as input and applies an expression to each
element in the array to return the final result of the
expression.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/zip.html#exp._S_zip" title="$zip"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$zip</span></code></a></td>
<td>Returns an output array where each element is itself an array,
consisting of elements in the corresponding array index position
from the input arrays.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="new-aggregation-string-operators">
<h3>New Aggregation String Operators<a class="headerlink" href="#new-aggregation-string-operators" title="Permalink to this headline">¶</a></h3>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Operator</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/indexOfBytes.html#exp._S_indexOfBytes" title="$indexOfBytes"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$indexOfBytes</span></code></a></td>
<td>Searches a string for an occurence of a substring and returns
the UTF-8 byte index (zero-based) of the first occurence.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/indexOfCP.html#exp._S_indexOfCP" title="$indexOfCP"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$indexOfCP</span></code></a></td>
<td>Searches a string for an occurence of a substring and returns
the UTF-8 <a class="reference external" href="http://www.unicode.org/glossary/#code_point">code point</a> index
(zero-based) of the first occurence.</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/split.html#exp._S_split" title="$split"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$split</span></code></a></td>
<td>Splits a string by a specified delimiter into string components
and returns an array of the string components.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/strLenBytes.html#exp._S_strLenBytes" title="$strLenBytes"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$strLenBytes</span></code></a></td>
<td>Returns the number of UTF-8 bytes for a string.</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/strLenCP.html#exp._S_strLenCP" title="$strLenCP"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$strLenCP</span></code></a></td>
<td>Returns the number of UTF-8 <a class="reference external" href="http://www.unicode.org/glossary/#code_point">code points</a> for a string.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/substrBytes.html#exp._S_substrBytes" title="$substrBytes"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$substrBytes</span></code></a></td>
<td>Returns the substring of a string. The substring starts with the
character at the specified UTF-8 byte index (zero-based) in the
string for the length specified.</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/substrCP.html#exp._S_substrCP" title="$substrCP"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$substrCP</span></code></a></td>
<td>Returns the substring of a string. The substring starts with the
character at the specified UTF-8 <a class="reference external" href="http://www.unicode.org/glossary/#code_point">code point</a> index
(zero-based) in the string for the length specified.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="new-aggregation-control-flow-expression">
<h3>New Aggregation Control Flow Expression<a class="headerlink" href="#new-aggregation-control-flow-expression" title="Permalink to this headline">¶</a></h3>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Operator</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/switch.html#exp._S_switch" title="$switch"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$switch</span></code></a></td>
<td>Evaluates, in sequential order, the <code class="docutils literal"><span class="pre">case</span></code> expressions of the
specified branches to enter the first branch for which the
<code class="docutils literal"><span class="pre">case</span></code> expression evaluates to <code class="docutils literal"><span class="pre">true</span></code>.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="new-date-aggregation-operators">
<h3>New Date Aggregation Operators<a class="headerlink" href="#new-date-aggregation-operators" title="Permalink to this headline">¶</a></h3>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Operator</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/isoDayOfWeek.html#exp._S_isoDayOfWeek" title="$isoDayOfWeek"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$isoDayOfWeek</span></code></a></td>
<td>Returns the ISO 8601 weekday number, ranging from <code class="docutils literal"><span class="pre">1</span></code> (for
Monday) to <code class="docutils literal"><span class="pre">7</span></code> (for Sunday).</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/operator/aggregation/isoWeek.html#exp._S_isoWeek" title="$isoWeek"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$isoWeek</span></code></a></td>
<td>Returns the ISO 8601 week number, which can range from <code class="docutils literal"><span class="pre">1</span></code> to
<code class="docutils literal"><span class="pre">53</span></code>. Week numbers start at <code class="docutils literal"><span class="pre">1</span></code> with the week (Monday
through Sunday) that contains the year’s first Thursday.</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/isoWeekYear.html#exp._S_isoWeekYear" title="$isoWeekYear"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$isoWeekYear</span></code></a></td>
<td>Returns the ISO 8601 year number, where the year starts with the
Monday of week 1 (ISO 8601) and ends with the Sundays of the
last week (ISO 8601).</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="new-monitoring-aggregation-sources">
<h3>New Monitoring Aggregation Sources<a class="headerlink" href="#new-monitoring-aggregation-sources" title="Permalink to this headline">¶</a></h3>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="20%" />
<col width="80%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Operator</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/collStats.html#pipe._S_collStats" title="$collStats"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$collStats</span></code></a></td>
<td>Returns statistics regarding a collection or view.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="new-type-operator">
<h3>New Type Operator<a class="headerlink" href="#new-type-operator" title="Permalink to this headline">¶</a></h3>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="26%" />
<col width="74%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Operator</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/operator/aggregation/type.html#exp._S_type" title="$type"><code class="xref mongodb mongodb-expression docutils literal"><span class="pre">$type</span></code></a></td>
<td>Returns a string which specifies the
<a class="reference internal" href="../reference/bson-types.html"><span class="doc">BSON Types</span></a> of the argument.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="additional-changes">
<h3>Additional Changes<a class="headerlink" href="#additional-changes" title="Permalink to this headline">¶</a></h3>
<p><a class="reference internal" href="../reference/operator/aggregation/project.html#pipe._S_project" title="$project"><code class="xref mongodb mongodb-pipeline docutils literal"><span class="pre">$project</span></code></a> stage adds support for field exclusion in the
output document. Previously, you could only exclude the <code class="docutils literal"><span class="pre">_id</span></code> field
in the stage. If you specify the exclusion of a field or fields,</p>
<ul class="simple">
<li>All other fields are returned in the output documents.</li>
<li>You cannot specify new fields or the inclusion of other fields.</li>
</ul>
</div>
</div>
<div class="section" id="collation-and-case-insensitive-indexes">
<span id="relnotes-collation"></span><h2>Collation and Case-Insensitive Indexes<a class="headerlink" href="#collation-and-case-insensitive-indexes" title="Permalink to this headline">¶</a></h2>
<p>To allow for language-specific rules for string comparison, MongoDB
3.4 introduces <a class="reference internal" href="../reference/collation.html"><span class="doc">collation</span></a> to its query language and
indexes.</p>
<p>The following operations support collation:</p>
<table border="1" class="docutils">
<colgroup>
<col width="50%" />
<col width="50%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Commands</th>
<th class="head"><code class="docutils literal"><span class="pre">mongo</span></code> Shell Methods</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td><a class="reference internal" href="../reference/command/create.html#dbcmd.create" title="create"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">create</span></code></a></td>
<td><div class="first last line-block">
<div class="line"><a class="reference internal" href="../reference/method/db.createCollection.html#db.createCollection" title="db.createCollection()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.createCollection()</span></code></a></div>
<div class="line"><a class="reference internal" href="../reference/method/db.createView.html#db.createView" title="db.createView()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.createView()</span></code></a></div>
</div>
</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/command/createIndexes.html#dbcmd.createIndexes" title="createIndexes"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">createIndexes</span></code></a> <a class="footnote-reference" href="#index-restriction" id="id25">[1]</a></td>
<td><a class="reference internal" href="../reference/method/db.collection.createIndex.html#db.collection.createIndex" title="db.collection.createIndex()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.createIndex()</span></code></a> <a class="footnote-reference" href="#index-restriction" id="id26">[1]</a></td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/command/aggregate.html#dbcmd.aggregate" title="aggregate"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">aggregate</span></code></a></td>
<td><a class="reference internal" href="../reference/method/db.collection.aggregate.html#db.collection.aggregate" title="db.collection.aggregate()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.aggregate()</span></code></a></td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/command/distinct.html#dbcmd.distinct" title="distinct"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">distinct</span></code></a></td>
<td><a class="reference internal" href="../reference/method/db.collection.distinct.html#db.collection.distinct" title="db.collection.distinct()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.distinct()</span></code></a></td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/command/findAndModify.html#dbcmd.findAndModify" title="findAndModify"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">findAndModify</span></code></a></td>
<td><div class="first last line-block">
<div class="line"><a class="reference internal" href="../reference/method/db.collection.findAndModify.html#db.collection.findAndModify" title="db.collection.findAndModify()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.findAndModify()</span></code></a></div>
<div class="line"><a class="reference internal" href="../reference/method/db.collection.findOneAndDelete.html#db.collection.findOneAndDelete" title="db.collection.findOneAndDelete()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.findOneAndDelete()</span></code></a></div>
<div class="line"><a class="reference internal" href="../reference/method/db.collection.findOneAndReplace.html#db.collection.findOneAndReplace" title="db.collection.findOneAndReplace()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.findOneAndReplace()</span></code></a></div>
<div class="line"><a class="reference internal" href="../reference/method/db.collection.findOneAndUpdate.html#db.collection.findOneAndUpdate" title="db.collection.findOneAndUpdate()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.findOneAndUpdate()</span></code></a></div>
</div>
</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/command/find.html#dbcmd.find" title="find"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">find</span></code></a></td>
<td><a class="reference internal" href="../reference/method/cursor.collation.html#cursor.collation" title="cursor.collation()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">cursor.collation()</span></code></a> to specify collation for
<a class="reference internal" href="../reference/method/db.collection.find.html#db.collection.find" title="db.collection.find()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.find()</span></code></a></td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/command/mapReduce.html#dbcmd.mapReduce" title="mapReduce"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">mapReduce</span></code></a></td>
<td><a class="reference internal" href="../reference/method/db.collection.mapReduce.html#db.collection.mapReduce" title="db.collection.mapReduce()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.mapReduce()</span></code></a></td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/command/delete.html#dbcmd.delete" title="delete"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">delete</span></code></a></td>
<td><div class="first last line-block">
<div class="line"><a class="reference internal" href="../reference/method/db.collection.deleteOne.html#db.collection.deleteOne" title="db.collection.deleteOne()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.deleteOne()</span></code></a></div>
<div class="line"><a class="reference internal" href="../reference/method/db.collection.deleteMany.html#db.collection.deleteMany" title="db.collection.deleteMany()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.deleteMany()</span></code></a></div>
<div class="line"><a class="reference internal" href="../reference/method/db.collection.remove.html#db.collection.remove" title="db.collection.remove()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.remove()</span></code></a></div>
</div>
</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/command/update.html#dbcmd.update" title="update"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">update</span></code></a></td>
<td><div class="first last line-block">
<div class="line"><a class="reference internal" href="../reference/method/db.collection.update.html#db.collection.update" title="db.collection.update()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.update()</span></code></a></div>
<div class="line"><a class="reference internal" href="../reference/method/db.collection.updateOne.html#db.collection.updateOne" title="db.collection.updateOne()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.updateOne()</span></code></a>,</div>
<div class="line"><a class="reference internal" href="../reference/method/db.collection.updateMany.html#db.collection.updateMany" title="db.collection.updateMany()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.updateMany()</span></code></a>,</div>
<div class="line"><a class="reference internal" href="../reference/method/db.collection.replaceOne.html#db.collection.replaceOne" title="db.collection.replaceOne()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.replaceOne()</span></code></a></div>
</div>
</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/command/shardCollection.html#dbcmd.shardCollection" title="shardCollection"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">shardCollection</span></code></a></td>
<td><div class="first last line-block">
<div class="line"><a class="reference internal" href="../reference/method/sh.shardCollection.html#sh.shardCollection" title="sh.shardCollection()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">sh.shardCollection()</span></code></a></div>
</div>
</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/command/count.html#dbcmd.count" title="count"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">count</span></code></a></td>
<td><div class="first last line-block">
<div class="line"><a class="reference internal" href="../reference/method/db.collection.count.html#db.collection.count" title="db.collection.count()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.count()</span></code></a></div>
</div>
</td>
</tr>
<tr class="row-odd"><td>&#160;</td>
<td>Individual update, replace, and delete operations in
<a class="reference internal" href="../reference/method/db.collection.bulkWrite.html#db.collection.bulkWrite" title="db.collection.bulkWrite()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.collection.bulkWrite()</span></code></a>.</td>
</tr>
</tbody>
</table>
<p>For details, see <a class="reference internal" href="../reference/collation.html"><span class="doc">Collation</span></a>.</p>
<table class="docutils footnote" frame="void" id="index-restriction" rules="none">
<colgroup><col class="label" /><col /></colgroup>
<tbody valign="top">
<tr><td class="label">[1]</td><td><em>(<a class="fn-backref" href="#id25">1</a>, <a class="fn-backref" href="#id26">2</a>)</em> Some index types do not support collation. See
<a class="reference internal" href="../reference/collation.html#collation-unsupported-index-types"><span class="std std-ref">Collation and Unsupported Index Types</span></a> for details.</td></tr>
</tbody>
</table>
</div>
<div class="section" id="views">
<span id="relnotes-views"></span><h2>Views<a class="headerlink" href="#views" title="Permalink to this headline">¶</a></h2>
<p>MongoDB 3.4 adds support for creating read-only views from existing
collections or other views. To specify or define a view, MongoDB 3.4
introduces:</p>
<ul>
<li><p class="first">the <code class="docutils literal"><span class="pre">viewOn</span></code> and <code class="docutils literal"><span class="pre">pipeline</span></code> options to the existing
<a class="reference internal" href="../reference/command/create.html#dbcmd.create" title="create"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">create</span></code></a> command:</p>
<div class="button-code-block">
<div class="button-row">
<a class="code-button--copy code-button" role="button">
copy</a>
</div>
<div class="copyable-code-block highlight-javascript"><div class="highlight"><pre><span></span><span class="nx">db</span><span class="p">.</span><span class="nx">runCommand</span><span class="p">(</span> <span class="p">{</span> <span class="nx">create</span><span class="o">:</span> <span class="o">&lt;</span><span class="nx">view</span><span class="o">&gt;</span><span class="p">,</span> <span class="nx">viewOn</span><span class="o">:</span> <span class="o">&lt;</span><span class="nx">source</span><span class="o">&gt;</span><span class="p">,</span> <span class="nx">pipeline</span><span class="o">:</span> <span class="o">&lt;</span><span class="nx">pipeline</span><span class="o">&gt;</span> <span class="p">}</span> <span class="p">)</span>
</pre></div>
</div>
</div>
<p>or if specifying a default <a class="reference internal" href="#relnotes-collation"><span class="std std-ref">collation</span></a> for the view:</p>
<div class="button-code-block">
<div class="button-row">
<a class="code-button--copy code-button" role="button">
copy</a>
</div>
<div class="copyable-code-block highlight-javascript"><div class="highlight"><pre><span></span><span class="nx">db</span><span class="p">.</span><span class="nx">runCommand</span><span class="p">(</span> <span class="p">{</span> <span class="nx">create</span><span class="o">:</span> <span class="o">&lt;</span><span class="nx">view</span><span class="o">&gt;</span><span class="p">,</span> <span class="nx">viewOn</span><span class="o">:</span> <span class="o">&lt;</span><span class="nx">source</span><span class="o">&gt;</span><span class="p">,</span> <span class="nx">pipeline</span><span class="o">:</span> <span class="o">&lt;</span><span class="nx">pipeline</span><span class="o">&gt;</span><span class="p">,</span> <span class="nx">collation</span><span class="o">:</span> <span class="o">&lt;</span><span class="nx">collation</span><span class="o">&gt;</span> <span class="p">}</span> <span class="p">)</span>
</pre></div>
</div>
</div>
</li>
<li><p class="first">and a corresponding <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell helper
<a class="reference internal" href="../reference/method/db.createView.html#db.createView" title="db.createView()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.createView()</span></code></a>:</p>
<div class="button-code-block">
<div class="button-row">
<a class="code-button--copy code-button" role="button">
copy</a>
</div>
<div class="copyable-code-block highlight-javascript"><div class="highlight"><pre><span></span><span class="nx">db</span><span class="p">.</span><span class="nx">createView</span><span class="p">(</span><span class="o">&lt;</span><span class="nx">view</span><span class="o">&gt;</span><span class="p">,</span> <span class="o">&lt;</span><span class="nx">source</span><span class="o">&gt;</span><span class="p">,</span> <span class="o">&lt;</span><span class="nx">pipeline</span><span class="o">&gt;</span><span class="p">,</span> <span class="o">&lt;</span><span class="nx">collation</span><span class="o">&gt;</span><span class="p">)</span>
</pre></div>
</div>
</div>
</li>
</ul>
<p>For more information on creating views, see <a class="reference internal" href="../core/views.html#reference-views"><span class="std std-ref">Views</span></a>.</p>
</div>
<div class="section" id="security-enhancement">
<h2>Security Enhancement<a class="headerlink" href="#security-enhancement" title="Permalink to this headline">¶</a></h2>
<div class="section" id="transition-to-auth">
<h3>Transition to Auth<a class="headerlink" href="#transition-to-auth" title="Permalink to this headline">¶</a></h3>
<p>MongoDB 3.4 adds support for rolling transition to internal
authentication for replica sets and sharded clusters. For details, see
<a class="reference internal" href="../reference/configuration-options.html#security.transitionToAuth" title="security.transitionToAuth"><code class="xref mongodb mongodb-setting docutils literal"><span class="pre">security.transitionToAuth</span></code></a> setting and <code class="docutils literal"><span class="pre">--transitionToAuth</span></code>
command line option for <a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a> and <a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a>.</p>
<div class="admonition seealso">
<p class="first admonition-title">See also</p>
<p class="last"><a class="reference internal" href="../tutorial/enforce-keyfile-access-control-in-existing-replica-set-without-downtime.html"><span class="doc">Update Replica Set to Keyfile Authentication (No Downtime)</span></a></p>
</div>
</div>
<div class="section" id="user-roles-changes">
<h3>User Roles Changes<a class="headerlink" href="#user-roles-changes" title="Permalink to this headline">¶</a></h3>
<p>The privileges of the following built-in roles no longer apply to the
<code class="docutils literal"><span class="pre">local</span></code> and <code class="docutils literal"><span class="pre">config</span></code> databases:</p>
<table border="1" class="colwidths-given docutils">
<colgroup>
<col width="30%" />
<col width="70%" />
</colgroup>
<tbody valign="top">
<tr class="row-odd"><td><a class="reference internal" href="../reference/built-in-roles.html#readAnyDatabase" title="readAnyDatabase"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">readAnyDatabase</span></code></a></td>
<td>Starting in 3.4, to provide <code class="docutils literal"><span class="pre">read</span></code> privileges on the <code class="docutils literal"><span class="pre">local</span></code>
database, create a user in the <code class="docutils literal"><span class="pre">admin</span></code> database with
<a class="reference internal" href="../reference/built-in-roles.html#read" title="read"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">read</span></code></a> role in the <code class="docutils literal"><span class="pre">local</span></code> database. See also
<a class="reference internal" href="../reference/built-in-roles.html#clusterManager" title="clusterManager"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">clusterManager</span></code></a> and <a class="reference internal" href="../reference/built-in-roles.html#clusterMonitor" title="clusterMonitor"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">clusterMonitor</span></code></a> role
for access to the <code class="docutils literal"><span class="pre">config</span></code> and <code class="docutils literal"><span class="pre">local</span></code> databases.</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/built-in-roles.html#readWriteAnyDatabase" title="readWriteAnyDatabase"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">readWriteAnyDatabase</span></code></a></td>
<td>Starting in 3.4, to provide <code class="docutils literal"><span class="pre">readWrite</span></code> privileges on the
<code class="docutils literal"><span class="pre">local</span></code> database, create a user in the <code class="docutils literal"><span class="pre">admin</span></code> database with
<a class="reference internal" href="../reference/built-in-roles.html#readWrite" title="readWrite"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">readWrite</span></code></a> role in the <code class="docutils literal"><span class="pre">local</span></code> database. See also
<a class="reference internal" href="../reference/built-in-roles.html#clusterManager" title="clusterManager"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">clusterManager</span></code></a> and <a class="reference internal" href="../reference/built-in-roles.html#clusterMonitor" title="clusterMonitor"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">clusterMonitor</span></code></a> role
for access to the <code class="docutils literal"><span class="pre">config</span></code> and <code class="docutils literal"><span class="pre">local</span></code> databases.</td>
</tr>
<tr class="row-odd"><td><a class="reference internal" href="../reference/built-in-roles.html#userAdminAnyDatabase" title="userAdminAnyDatabase"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">userAdminAnyDatabase</span></code></a></td>
<td>&#160;</td>
</tr>
<tr class="row-even"><td><a class="reference internal" href="../reference/built-in-roles.html#dbAdminAnyDatabase" title="dbAdminAnyDatabase"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">dbAdminAnyDatabase</span></code></a></td>
<td>Starting in 3.4, to provide <code class="docutils literal"><span class="pre">dbAdmin</span></code> privileges on the
<code class="docutils literal"><span class="pre">local</span></code> database, create a user in the <code class="docutils literal"><span class="pre">admin</span></code> database with
<a class="reference internal" href="../reference/built-in-roles.html#dbAdmin" title="dbAdmin"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">dbAdmin</span></code></a> role in the <code class="docutils literal"><span class="pre">local</span></code> database. See also
<a class="reference internal" href="../reference/built-in-roles.html#clusterManager" title="clusterManager"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">clusterManager</span></code></a> and <a class="reference internal" href="../reference/built-in-roles.html#clusterMonitor" title="clusterMonitor"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">clusterMonitor</span></code></a> role
for access to the <code class="docutils literal"><span class="pre">config</span></code> and <code class="docutils literal"><span class="pre">local</span></code> databases.</td>
</tr>
</tbody>
</table>
<p>Correspondingly, the following built-in roles include additional read
and write privileges on <code class="docutils literal"><span class="pre">local</span></code> and <code class="docutils literal"><span class="pre">config</span></code> databases:</p>
<ul class="simple">
<li><a class="reference internal" href="../reference/built-in-roles.html#clusterManager" title="clusterManager"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">clusterManager</span></code></a></li>
<li><a class="reference internal" href="../reference/built-in-roles.html#clusterMonitor" title="clusterMonitor"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">clusterMonitor</span></code></a></li>
<li><a class="reference internal" href="../reference/built-in-roles.html#backup" title="backup"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">backup</span></code></a></li>
<li><a class="reference internal" href="../reference/built-in-roles.html#restore" title="restore"><code class="xref mongodb mongodb-authrole docutils literal"><span class="pre">restore</span></code></a>.</li>
</ul>
</div>
</div>
<div class="section" id="mongodb-tools">
<h2>MongoDB Tools<a class="headerlink" href="#mongodb-tools" title="Permalink to this headline">¶</a></h2>
<div class="section" id="mongoreplay">
<h3><code class="docutils literal"><span class="pre">mongoreplay</span></code><a class="headerlink" href="#mongoreplay" title="Permalink to this headline">¶</a></h3>
<p>MongoDB introduces <a class="reference internal" href="../reference/program/mongoreplay.html#bin.mongoreplay" title="bin.mongoreplay"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongoreplay</span></code></a>, a workload capture and
analysis tool that replaces <a class="reference internal" href="../reference/program/mongosniff.html#bin.mongosniff" title="bin.mongosniff"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongosniff</span></code></a>. You can use
<a class="reference internal" href="../reference/program/mongoreplay.html#bin.mongoreplay" title="bin.mongoreplay"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongoreplay</span></code></a> to inspect and record commands sent to a MongoDB
instance, and then replay the commands back onto another host at a
later time.</p>
<p><a class="reference internal" href="../reference/program/mongoreplay.html#bin.mongoreplay" title="bin.mongoreplay"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongoreplay</span></code></a> is available for Linux and macOS.</p>
</div>
</div>
<div class="section" id="general-enhancements">
<h2>General Enhancements<a class="headerlink" href="#general-enhancements" title="Permalink to this headline">¶</a></h2>
<p>MongoDB 3.4 includes the following enhancements:</p>
<ul class="simple">
<li>Added <code class="docutils literal"><span class="pre">systemd</span></code> support in distributions.</li>
<li>Increased <a class="reference internal" href="../reference/parameters.html#param.diagnosticDataCollectionDirectorySizeMB" title="diagnosticDataCollectionDirectorySizeMB"><code class="xref mongodb mongodb-parameter docutils literal"><span class="pre">diagnosticDataCollectionDirectorySizeMB</span></code></a>
default size to 200 megabytes from 100 megabytes.</li>
<li>Decreased the lower bound and the default setting of the
<a class="reference internal" href="../reference/program/mongod.html#cmdoption-mongod-wiredtigercachesizegb"><code class="xref std std-option docutils literal"><span class="pre">WiredTiger</span> <span class="pre">internal</span> <span class="pre">cache</span></code></a>. Both
the <a class="reference internal" href="../reference/program/mongod.html#cmdoption-mongod-wiredtigercachesizegb"><code class="xref std std-option docutils literal"><span class="pre">WiredTiger</span> <span class="pre">Storage</span> <span class="pre">Engine</span> <span class="pre">internal</span> <span class="pre">cache</span></code></a> and the <a class="reference internal" href="../reference/program/mongod.html#cmdoption-mongod-inmemorysizegb"><code class="xref std std-option docutils literal"><span class="pre">inMemory</span> <span class="pre">Storage</span> <span class="pre">Engine</span>
<span class="pre">maximum</span> <span class="pre">memory</span> <span class="pre">size</span></code></a> can accept floating-point values.</li>
<li><a class="reference internal" href="../reference/method/db.collection.find.html#db.collection.find" title="db.collection.find()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">find()</span></code></a>,
<a class="reference internal" href="../reference/method/db.collection.aggregate.html#db.collection.aggregate" title="db.collection.aggregate()"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">aggregate()</span></code></a>, <a class="reference internal" href="../reference/command/listIndexes.html#dbcmd.listIndexes" title="listIndexes"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">listIndexes</span></code></a>, and
<a class="reference internal" href="../reference/command/listCollections.html#dbcmd.listCollections" title="listCollections"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">listCollections</span></code></a> operations return a <a class="reference internal" href="../tutorial/iterate-a-cursor.html#cursor-batches"><span class="std std-ref">maximum of 16
megabytes per batch</span></a>.</li>
</ul>
<p><a class="reference internal" href="../reference/method/db.currentOp.html#db.currentOp" title="db.currentOp"><code class="xref mongodb mongodb-method docutils literal"><span class="pre">db.currentOp</span></code></a> and the
<a class="reference internal" href="../reference/database-profiler.html"><span class="doc">database profiler</span></a> report the same
basic diagnostic information for all CRUD operations, including the
following:</p>
<ul>
<li><ul class="first simple">
<li><a class="reference internal" href="../reference/command/aggregate.html#dbcmd.aggregate" title="aggregate"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">aggregate</span></code></a></li>
<li><a class="reference internal" href="../reference/command/count.html#dbcmd.count" title="count"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">count</span></code></a></li>
<li><a class="reference internal" href="../reference/command/delete.html#dbcmd.delete" title="delete"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">delete</span></code></a></li>
<li><a class="reference internal" href="../reference/command/distinct.html#dbcmd.distinct" title="distinct"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">distinct</span></code></a></li>
<li><code class="docutils literal"><span class="pre">find</span></code> (<a class="reference internal" href="../reference/mongodb-wire-protocol.html#wire-op-query"><span class="std std-ref">OP_QUERY</span></a> and
<a class="reference internal" href="../reference/command/find.html#dbcmd.find" title="find"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">command</span></code></a>)</li>
<li><a class="reference internal" href="../reference/command/findAndModify.html#dbcmd.findAndModify" title="findAndModify"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">findAndModify</span></code></a></li>
<li><code class="docutils literal"><span class="pre">getMore</span></code> (<a class="reference internal" href="../reference/mongodb-wire-protocol.html#wire-op-query"><span class="std std-ref">OP_GET_MORE</span></a> and
<a class="reference internal" href="../reference/command/getMore.html#dbcmd.getMore" title="getMore"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">command</span></code></a>)</li>
<li><a class="reference internal" href="../reference/command/insert.html#dbcmd.insert" title="insert"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">insert</span></code></a></li>
<li><a class="reference internal" href="../reference/command/mapReduce.html#dbcmd.mapReduce" title="mapReduce"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">mapReduce</span></code></a></li>
<li><a class="reference internal" href="../reference/command/update.html#dbcmd.update" title="update"><code class="xref mongodb mongodb-dbcommand docutils literal"><span class="pre">update</span></code></a></li>
</ul>
<p>These operations are also included in the logging of
slow queries (see <a class="reference internal" href="../reference/configuration-options.html#operationProfiling.slowOpThresholdMs" title="operationProfiling.slowOpThresholdMs"><code class="xref mongodb mongodb-setting docutils literal"><span class="pre">slowOpThresholdMs</span></code></a> for
more information about slow query logging).</p>
</li>
<li><p class="first"><a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell adds support for marshalling fields of type
<a class="reference internal" href="../reference/bson-types.html#bson-types"><span class="std std-ref">javascript</span></a> and
<a class="reference internal" href="../reference/bson-types.html#bson-types"><span class="std std-ref">javascriptWithScope</span></a> to JavaScript functions.
See <a class="reference internal" href="../reference/program/mongo.html#cmdoption-mongo-disablejavascriptprotection"><code class="xref std std-option docutils literal"><span class="pre">--disableJavaScriptProtection</span></code></a>.</p>
</li>
<li><p class="first">Added support for system certificates. If a <a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a>
instance presents a certificate signed with a CA trusted by the
operating system, the <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell will connect without any
errors. Previously, the <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell exited with an error
that it could not validate the certificate.</p>
</li>
<li><p class="first">Added message compression support for internal communication between
members of a replica set or a sharded cluster as well as
communication between <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell and <a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a> or
<a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a>.</p>
<p>See configuration <a class="reference internal" href="../reference/configuration-options.html#net.compression.compressors" title="net.compression.compressors"><code class="xref mongodb mongodb-setting docutils literal"><span class="pre">net.compression.compressors</span></code></a> setting as
well as the <code class="docutils literal"><span class="pre">--networkMessageCompressors</span></code> option for
<a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a>, <a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a>, and the <a class="reference internal" href="../reference/program/mongo.html#bin.mongo" title="bin.mongo"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongo</span></code></a> shell.</p>
</li>
<li><p class="first">Upgraded the SpiderMonkey JavaScript engine to 45.0.2 ESR.</p>
</li>
</ul>
</div>
<div class="section" id="platform-support">
<h2>Platform Support<a class="headerlink" href="#platform-support" title="Permalink to this headline">¶</a></h2>
<ul class="simple">
<li>MongoDB 3.4 introduces support for ARM64, PPC64LE, and s390x
architectures. See <a class="reference internal" href="../administration/production-notes.html#prod-notes-supported-platforms"><span class="std std-ref">Supported Platforms</span></a> to see the
full platform support matrix.</li>
<li>Starting in version 3.4, MongoDB removes support for Red Hat Enterprise Linux 5.</li>
</ul>
<p>For earlier MongoDB Enterprise versions that support Ubuntu 16.04
POWER/PPC64LE:</p>
<p>Due to a lock elision bug present in older versions
of the <code class="docutils literal"><span class="pre">glibc</span></code> package on Ubuntu 16.04 for POWER, you must
upgrade the <code class="docutils literal"><span class="pre">glibc</span></code> package to at least <code class="docutils literal"><span class="pre">glibc</span> <span class="pre">2.23-0ubuntu5</span></code>
before running MongoDB. Systems with older versions of the
<code class="docutils literal"><span class="pre">glibc</span></code> package will experience database server crashes and
misbehavior due to random memory corruption, and are unsuitable
for production deployments of MongoDB</p>
<p>The following summarizes the supported architecture for the latest
version of MongoDB products:</p>
<table border="1" class="docutils">
<colgroup>
<col width="20%" />
<col width="20%" />
<col width="20%" />
<col width="20%" />
<col width="20%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Product</th>
<th class="head">x86_64/amd64</th>
<th class="head">s390x</th>
<th class="head">POWER8 (little endian)</th>
<th class="head">ARMv8-A</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>MongoDB 3.4</td>
<td>✓</td>
<td>MongoDB Enterprise only</td>
<td>MongoDB Enterprise only</td>
<td>✓</td>
</tr>
<tr class="row-odd"><td><a class="reference external" href="https://docs.mongodb.com/bi-connector/v2.0/">BI Connector</a></td>
<td>✓</td>
<td>✓</td>
<td>✓</td>
<td>&#160;</td>
</tr>
<tr class="row-even"><td><a class="reference external" href="https://docs.mongodb.com/compass/current/">Compass</a></td>
<td>✓</td>
<td>&#160;</td>
<td>&#160;</td>
<td>&#160;</td>
</tr>
<tr class="row-odd"><td><a class="reference external" href="https://docs.mongodb.com/spark-connector/v2.0/">Spark Connector</a></td>
<td>✓</td>
<td>&#160;</td>
<td>&#160;</td>
<td>&#160;</td>
</tr>
<tr class="row-even"><td><a class="reference external" href="https://docs.opsmanager.mongodb.com/current/">Ops Manager</a></td>
<td>✓</td>
<td>&#160;</td>
<td>&#160;</td>
<td>&#160;</td>
</tr>
<tr class="row-odd"><td>Automation Agent</td>
<td>✓</td>
<td>&#160;</td>
<td>✓</td>
<td>&#160;</td>
</tr>
<tr class="row-even"><td>Monitoring Agent</td>
<td>✓</td>
<td>&#160;</td>
<td>✓</td>
<td>&#160;</td>
</tr>
<tr class="row-odd"><td>Backup Agent</td>
<td>✓</td>
<td>&#160;</td>
<td>✓</td>
<td>&#160;</td>
</tr>
</tbody>
</table>
<p>For details, refer to the individual documentation for the products.</p>
</div>
<div class="section" id="mongodb-enterprise-features">
<h2>MongoDB Enterprise Features<a class="headerlink" href="#mongodb-enterprise-features" title="Permalink to this headline">¶</a></h2>
<div class="section" id="log-redaction">
<h3>Log Redaction<a class="headerlink" href="#log-redaction" title="Permalink to this headline">¶</a></h3>
<p>MongoDB Enterprise adds support for log redaction for use in
conjunction with MongoDB’s <a class="reference internal" href="../core/security-encryption-at-rest.html"><span class="doc">encrypted storage engine</span></a>. Log redaction prevents
potentially sensitive information from being written to the diagnostic
log; however, diagnostics on redacted logs may be more difficult due to
the lack of data related to a log event.</p>
<p>To enable log redaction, see the
<a class="reference internal" href="../reference/configuration-options.html#security.redactClientLogData" title="security.redactClientLogData"><code class="xref mongodb mongodb-setting docutils literal"><span class="pre">security.redactClientLogData</span></code></a> setting and the
<a class="reference internal" href="../reference/program/mongod.html#cmdoption-mongod-redactclientlogdata"><code class="xref std std-option docutils literal"><span class="pre">--redactClientLogData</span></code></a> option for <a class="reference internal" href="../reference/program/mongod.html#bin.mongod" title="bin.mongod"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongod</span></code></a>.</p>
</div>
<div class="section" id="ldap-enhancements">
<h3>LDAP Enhancements<a class="headerlink" href="#ldap-enhancements" title="Permalink to this headline">¶</a></h3>
<div class="section" id="ldap-authorization">
<h4>LDAP Authorization<a class="headerlink" href="#ldap-authorization" title="Permalink to this headline">¶</a></h4>
<p>MongoDB Enterprise supports the use of <a class="reference internal" href="../core/security-ldap-external.html"><span class="doc">Lightweight Directory
Access Protocol (LDAP) service to authorize (i.e. determine access)</span></a> a user authenticated via one of the
following authentication mechanism:</p>
<ul class="simple">
<li><a class="reference internal" href="../core/security-ldap.html"><span class="doc">LDAP Proxy Authentication</span></a>. For a tutorial on using both LDAP
Authentication and Authorization, see
<a class="reference internal" href="../tutorial/authenticate-nativeldap-activedirectory.html"><span class="doc">Authenticate and Authorize Users Using Active Directory via Native LDAP</span></a>.</li>
<li><a class="reference internal" href="../core/kerberos.html"><span class="doc">Kerberos Authentication</span></a>. For a tutorial on using Kerberos
authentication and Active Directory, see
<a class="reference internal" href="../tutorial/kerberos-auth-activedirectory-authz.html"><span class="doc">Configure MongoDB with Kerberos Authentication and Active Directory Authorization</span></a>.</li>
<li><a class="reference internal" href="../core/security-x.509.html"><span class="doc">x.509</span></a>.</li>
</ul>
<p>For more information, see <a class="reference internal" href="../core/security-ldap-external.html"><span class="doc">LDAP Authorization</span></a>.</p>
</div>
<div class="section" id="mongoldap">
<h4><code class="docutils literal"><span class="pre">mongoldap</span></code><a class="headerlink" href="#mongoldap" title="Permalink to this headline">¶</a></h4>
<p>MongoDB Enterprise provides a new tool <a class="reference internal" href="../reference/program/mongoldap.html#bin.mongoldap" title="bin.mongoldap"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongoldap</span></code></a> for testing
your MongoDB <a class="reference internal" href="../reference/configuration-options.html#security-ldap-options"><span class="std std-ref">LDAP configuration options</span></a>
against a running LDAP server or set of servers. When configuring
options related to <a class="reference internal" href="../core/security-ldap.html#security-ldap"><span class="std std-ref">LDAP authentication</span></a>, you can
use <a class="reference internal" href="../reference/program/mongoldap.html#bin.mongoldap" title="bin.mongoldap"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongoldap</span></code></a> to ensure that the authentication operation
works as expected.</p>
</div>
<div class="section" id="bind-via-os-libraries">
<h4>Bind via OS Libraries<a class="headerlink" href="#bind-via-os-libraries" title="Permalink to this headline">¶</a></h4>
<p>MongoDB 3.4 supports <a class="reference internal" href="../core/security-ldap.html"><span class="doc">binding to an LDAP server</span></a> via operating system libraries. This allows
Linux and Windows MongoDB 3.4 servers to use an LDAP server for
authentication.</p>
<p>Linux MongoDB deployments continue to support binding via <a class="reference external" href="http://www.linuxcommand.org/man_pages/saslauthd8.html">saslauthd</a>.</p>
</div>
</div>
</div>
<div class="section" id="changes-affecting-compatibility">
<h2>Changes Affecting Compatibility<a class="headerlink" href="#changes-affecting-compatibility" title="Permalink to this headline">¶</a></h2>
<p>Some changes can affect compatibility and may require user actions. For
a detailed list of compatibility changes, see
<a class="reference internal" href="3.4-compatibility.html"><span class="doc">Compatibility Changes in MongoDB 3.4</span></a>.</p>
<div class="toctree-wrapper hidden compound">
<ul>
<li class="toctree-l1"><a class="reference internal" href="3.4-compatibility.html">Compatibility Changes in MongoDB 3.4</a><ul>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#sharded-cluster-changes">Sharded Cluster Changes</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html#shardsvr-requirement"><code class="docutils literal"><span class="pre">shardsvr</span></code> Requirement</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html#mongos-and-earlier-versions-of-mongod">3.4 <code class="docutils literal"><span class="pre">mongos</span></code> and Earlier Versions of <code class="docutils literal"><span class="pre">mongod</span></code></a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html#removal-for-configuration-options">Removal for Configuration Options</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html#removal-of-support-for-sccc-config-servers">Removal of Support for SCCC Config Servers</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#initial-sync-and-renamecollection">Initial Sync and <code class="docutils literal"><span class="pre">renameCollection</span></code></a></li>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#deprecated-operations">Deprecated Operations</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html#group"><code class="docutils literal"><span class="pre">group</span></code></a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html#aggregate-without-cursor"><code class="docutils literal"><span class="pre">aggregate</span></code> without <code class="docutils literal"><span class="pre">cursor</span></code></a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#stricter-validation-of-collection-and-index-specifications">Stricter Validation of Collection and Index Specifications</a><ul>
<li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html#stricter-validation-of-collection-options">Stricter Validation of Collection Options</a></li>
<li class="toctree-l3"><a class="reference internal" href="3.4-compatibility.html#stricter-validation-of-index-specifications">Stricter Validation of Index Specifications</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#general-compatibility-changes">General Compatibility Changes</a></li>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#user-roles-changes">User Roles Changes</a></li>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#backwards-incompatible-features">Backwards Incompatible Features</a></li>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#driver-compatibility-changes">Driver Compatibility Changes</a></li>
<li class="toctree-l2"><a class="reference internal" href="3.4-compatibility.html#single-element-in-with-upsert">Single Element <code class="docutils literal"><span class="pre">$in</span></code> With <code class="docutils literal"><span class="pre">upsert</span></code></a></li>
</ul>
</li>
</ul>
</div>
</div>
<div class="section" id="upgrade-procedures">
<span id="upgrade"></span><h2>Upgrade Procedures<a class="headerlink" href="#upgrade-procedures" title="Permalink to this headline">¶</a></h2>
<ul class="simple">
<li><a class="reference internal" href="3.4-upgrade-standalone.html"><span class="doc">Upgrade a Standalone to 3.4</span></a>.</li>
<li><a class="reference internal" href="3.4-upgrade-replica-set.html"><span class="doc">Upgrade a Replica Set to 3.4</span></a>.</li>
<li><a class="reference internal" href="3.4-upgrade-sharded-cluster.html"><span class="doc">Upgrade a Sharded Cluster to 3.4</span></a>.</li>
</ul>
<p>If you need guidance on upgrading to 3.4, <a class="reference external" href="https://www.mongodb.com/products/consulting?jmp=docs">MongoDB offers major version
upgrade services</a>
to help ensure a smooth transition without interruption to your MongoDB application.</p>
</div>
<div class="section" id="download">
<h2>Download<a class="headerlink" href="#download" title="Permalink to this headline">¶</a></h2>
<p>To download the MongoDB 3.4, go to the <a class="reference external" href="https://www.mongodb.com/download-center?jmp=docs">MongoDB Download Center</a></p>
<div class="admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference external" href="https://github.com/mongodb/mongo/blob/v3.4/distsrc/THIRD-PARTY-NOTICES">All Third Party License Notices</a>.</li>
</ul>
</div>
<div class="toctree-wrapper hidden compound">
<ul>
<li class="toctree-l1"><a class="reference internal" href="3.4-upgrade-standalone.html">Upgrade a Standalone to 3.4</a></li>
<li class="toctree-l1"><a class="reference internal" href="3.4-upgrade-replica-set.html">Upgrade a Replica Set to 3.4</a></li>
<li class="toctree-l1"><a class="reference internal" href="3.4-upgrade-sharded-cluster.html">Upgrade a Sharded Cluster to 3.4</a></li>
<li class="toctree-l1"><a class="reference internal" href="3.4-downgrade.html">Downgrade MongoDB 3.4 to 3.2</a><ul>
<li class="toctree-l2"><a class="reference internal" href="3.4-downgrade-standalone.html">Downgrade 3.4 Standalone to 3.2</a></li>
<li class="toctree-l2"><a class="reference internal" href="3.4-downgrade-replica-set.html">Downgrade 3.4 Replica Set to 3.2</a></li>
<li class="toctree-l2"><a class="reference internal" href="3.4-downgrade-sharded-cluster.html">Downgrade 3.4 Sharded Cluster to 3.2</a></li>
</ul>
</li>
</ul>
</div>
</div>
<div class="section" id="known-issues-in-3-4-0">
<h2>Known Issues in 3.4.0<a class="headerlink" href="#known-issues-in-3-4-0" title="Permalink to this headline">¶</a></h2>
<p>List of known issues in the 3.4.0 release:</p>
<ul class="simple">
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27124">SERVER-27124</a>: <a class="reference internal" href="../reference/replica-configuration.html#rsconf.protocolVersion" title="protocolVersion"><code class="xref mongodb mongodb-rsconf docutils literal"><span class="pre">protocolVersion:</span> <span class="pre">0</span></code></a>
cannot properly support <a class="reference internal" href="../reference/read-concern-majority.html#readconcern.&quot;majority&quot;" title="&quot;majority&quot;"><code class="xref mongodb mongodb-readconcern docutils literal"><span class="pre">&quot;majority&quot;</span></code></a> read concern.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27195">SERVER-27195</a>: Using collation with documents containing
fields of BSON type <code class="docutils literal"><span class="pre">Symbol</span></code>, which is deprecated, is not supported
and may lead to undefined behavior.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/SERVER-27207">SERVER-27207</a>: Find on view with sort through
<a class="reference internal" href="../reference/program/mongos.html#bin.mongos" title="bin.mongos"><code class="xref mongodb mongodb-binary docutils literal"><span class="pre">mongos</span></code></a> may incorrectly return empty result set.</li>
<li><a class="reference external" href="https://jira.mongodb.org/browse/WT-3327">WT-3327</a>: <a class="reference internal" href="../core/wiredtiger.html#storage-wiredtiger-checkpoints"><span class="std std-ref">Checkpoints</span></a>
can hang if time runs backwards (e.g.
on a system with an unreliable clock).
(Fixed in <a class="reference internal" href="#id17"><span class="std std-ref">MongoDB 3.4.6</span></a>.)</li>
</ul>
</div>
</div>

                
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